Showing posts with label space. Show all posts
Showing posts with label space. Show all posts

Saturday, February 27, 2016

Discovery Channel Large Asteroid Impact Simulation YouTube

Discovery Channel Large Asteroid Impact Simulation YouTube




Discovery Channel Large Asteroid Impact Simulation

● Discovery Channel - Large Asteroid Impact Simulation (2008).

Earth was born as a result of repeated asteroid collisions, the moon was created by a single giant impact event. Then, Earth's size attracted huge meteorites, which slammed into it, causing super-high-temperature rock vapour to cover the entire surface and evaporate all ocean water. The earliest life-forms survived such infernal events by escaping deep into the ground, miraculously emerging again and again. The Earth has gone through innumerable catastrophic events, and life has survived by acquiring new abilities to live through each crisis. Humans are part of the grand history of life's evolution, which has been closely intertwined with repeated cataclysmic events.

Learn what would happen if an asteroid hit the Earth with this detailed "Large Asteroid Impact Simulation".
An asteroid with a diameter of 500 km. Destination: The Pacific Ocean. The impact peels the 10 km crust off the surface. The shockwave travels at hypersonic speeds. Debris is blasted across into low Earth orbit, and returns to destroy the surface of the Earth. The firestorm encircles the Earth, vaporizing all life in its way. Within one day, the surface of the Earth is uninhabitable. The evidence shows that this has happened at least six times in Earth's history.
Music of Pink Floyd "The Great Gig in the Sky" (1973).

0:12 An asteroid with a diameter of 500 km.
0:47 Destination: The Pacific Ocean.
1:17 The impact peels the 10 km crust off the surface.
1:28 The shockwave travels at hypersonic speeds.
1:53 Debris is blasted across into low Earth orbit,
2:11 and returns to destroy the surface of the Earth.
2:55 The firestorm encircles the Earth,
3:05 vaporizing all life in its way.
3:34 Within one day, the surface of the Earth is uninhabitable.
4:19 The evidence shows that this has happened at least six times in Earth's history.


● Discovery Channel - Simulazione di impatto con un asteroide di grandi dimensioni (2008).

La Terra è nata a seguito di ripetute collisioni di asteroidi, la luna è stata creata da un singolo impatto gigantesco. Poi, le dimensioni della Terra hanno attratto enormi meteoriti, che si sono schiantate su di essa, causando vapori di roccia ad altissima temperatura che hanno ricoperto l'intera superficie e fatto evaporare tutta l'acqua dell'oceano. Le prime forme di vita sono sopravvissute a tali eventi infernali fuggendo in profondità nel terreno, emergendo miracolosamente ancora e ancora. La Terra è passata attraverso innumerevoli eventi catastrofici, e la vita è sopravvissuta attraverso l'acquisizione di nuove capacità per vivere attraverso ogni crisi. Gli esseri umani sono parte della grande storia dell'evoluzione della vita, che è stata strettamente intrecciata con ripetuti eventi catastrofici.

Apprendi che cosa accadrebbe se un asteroide colpisse la Terra, con questa dettagliata "Simulazione di impatto con un asteroide di grandi dimensioni".
Un asteroide con un diametro di 500 km. Destinazione: l'Oceano Pacifico. L'impatto spella i 10 km di crosta via dalla superficie. L'onda d'urto viaggia a velocità ipersonica. I detriti vengono scagliati tutti in orbita terrestre bassa, e ritornano per distruggere la superficie della Terra. La tempesta di fuoco circonda la Terra, vaporizzando tutta la vita in questo modo. Entro un giorno, la superficie della Terra è inabitabile. Le prove dimostrano che questo è avvenuto almeno sei volte nella storia della Terra.
Musica dei Pink Floyd "The Great Gig in the Sky" (1973).

0:12 Un asteroide con un diametro di 500 km.
0:47 Destinazione: l'Oceano Pacifico.
1:17 L'impatto spella i 10 km di crosta via dalla superficie.
1:28 L'onda d'urto viaggia a velocità ipersonica.
1:53 I detriti vengono scagliati tutti in orbita terrestre bassa,
2:11 e ritornano per distruggere la superficie della Terra.
2:55 La tempesta di fuoco circonda la Terra,
3:05 vaporizzando tutta la vita in questo modo.
3:34 Entro un giorno, la superficie della Terra è inabitabile.
4:19 Le prove dimostrano che questo è avvenuto almeno sei volte nella storia della Terra.

Tuesday, December 8, 2015

MUST READ : Order Of the Planets From The Sun

Order Of the Planets From The Sun:

Planets and other objects in our Solar System. Credit: NASA.


Planets and other objects in our Solar System. Credit: NASA.
Remembering the order of the planets can be a tricky task. With eight celestial bodies, and all the names taken from classical nomenclature, getting them mixed up is a common mistake. First the quick facts: Our Solar System has eight “official” planets which orbit the Sun. Here are the planets listed in order of their distance from the Sun:

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. An easy mnemonic for remembering the order is “My Very Educated Mother Just Served Us Noodles.”

If you add in the dwarf planets, Ceres is located in the asteroid belt between Mars and Jupiter, while the remaining dwarf planets are in the outer Solar System and in order from the Sun are Pluto, Haumea, Makemake, and Eris. There is, as yet, a bit of indecision about the Trans-Neptunian Objects known as Orcus, Quaoar, 2007 O10, and Sedna and their inclusion in the dwarf planet category.

A mnemonic for this list would be “My Very Educated Mother Could Just Serve Us Noodles, Pie, Ham, Muffins, and Eggs” (and Steak, if Sedna is included.) Now, let’s look at a few details including the definition of a planet and a dwarf planet, as well as details about each of the planets in our Solar System.



The Solar System. Image Credit: NASA


Artistic impression of the Solar System, with all known terrestrial planets, as giants, and dwarf planets. Credit: NASA
What is a planet?
In 2006, the International Astronomical Union (IAU) decided on the definition of a planet. The definition states that in our Solar System, a planet is a celestial body which:

  • is in orbit around the Sun,
  • has sufficient mass to assume hydrostatic equilibrium (a nearly round shape),
  • has “cleared the neighborhood” around its orbit.
  • is not a moon.
This means that Pluto, which was considered to be the farthest planet since its discovery in 1930, now is classified as a dwarf planet. The change in the definition came after the discovery three bodies that were all similar to Pluto in terms of size and orbit, (Quaoar in 2002, Sedna in 2003, and Eris in 2005).

With advances in equipment and techniques, astronomers knew that more objects like Pluto would very likely be discovered, and so the number of planets in our Solar System would start growing quickly. It soon became clear that either they all had to be called planets or Pluto and bodies like it would have to be reclassified.



With much controversy then and since, Pluto was reclassified as a dwarf planet in 2006. This also reclassified the asteroid Ceres as a dwarf planet, too, and so the first five recognized dwarf planets are Ceres, Pluto, Eris, Makemake and Haumea. Scientists believe there may be dozens more dwarf planets awaiting discovery.

Later, in 2008, the IAU announced the subcategory of dwarf planets with trans-Neptunian orbits would be known as “plutoids.” Said the IAU, “Plutoids are celestial bodies in orbit around the Sun at a distance greater than that of Neptune that have sufficient mass for their self-gravity to overcome rigid body forces so that they assume a hydrostatic equilibrium (near-spherical) shape, and that have not cleared the neighborhood around their orbit.”

This subcategory includes Ceres, Pluto, Haumea, Makemake, and Eris.

The Planets in our Solar System:
Having covered the basics of definition and classification, let’s get talking about those celestial bodies in our Solar System that are still classified as planets (sorry Pluto!). Here is a brief look at the eight planets in our Solar System. Included are quick facts and links so you can find out more about each planet.

Mercury:Mercury is the closest planet to our Sun, at just 58 million km (36 million miles) or 0.39 Astronomical Unit (AU) out. But despite its reputation for being sun-baked and molten, it is not the hottest planet in our Solar System (scroll down to find out who that dubious honor goes go!)



Mercury, as imaged by the MESSENGER spacecraft, revealing parts of the never seen by human eyes. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington


Mercury, as imaged by the MESSENGER spacecraft, revealing parts of the never seen by human eyes. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Mercury is also the smallest planet in our Solar System, and is also smaller than its largest moon (Ganymede, which orbits Jupiter). And being equivalent in size to 0.38 Earths, it is just slightly larger than the Earth’s own Moon. But this may have something to do with its incredible density, being composed primarily of rock and iron ore. Here are the planetary facts:

  • Diameter: 4,879 km (3,032 miles)
  • Mass: 3.3011 x 1023 kg (0.055 Earths)
  • Length of Year (Orbit): 87.97 Earth days
  • Length of Day: 59 Earth days.
  • Mercury is a rocky planet, one of the four “terrestrial planets” in our Solar System. Mercury has a solid, cratered surface, and looks much like Earth’s moon.
  • If you weigh 45 kg (100 pounds) on Earth, you would weigh 17 kg (38 pounds) on Mercury.
  • Mercury does not have any moons.
  • Temperatures on Mercury range between -173 to 427 degrees Celcius (-279 to 801 degrees Fahrenheit)
  • Just two spacecraft have visited Mercury: Mariner 10 in 1974-75 and MESSENGER, which flew past Mercury three times before going into orbit around Mercury in 2011 and ended its mission by impacting the surface of Mercury on April 30, 2015. MESSENGER has changed our understanding of this planet, and scientists are still studying the data.
  • Find more details about Mercury at this article on Universe Today, and this page from NASA.
Venus:
Venus is the second closest planet to our Sun, orbiting at an average distance of 108 million km (67 million miles) or 0.72 AU. Venus is often called Earth’s “sister planet,” as it is just a little smaller than Earth. Venus is 81.5% as massive as Earth, and has 90% of its surface area and 86.6% of its volume. The surface gravity, which is 8.87 m/s², is equivalent to 0.904 – roughly 90% of the Earth standard.



A radar view of Venus taken by the Magellan spacecraft, with some gaps filled in by the Pioneer Venus orbiter. Credit: NASA/JPL


A radar view of Venus taken by the Magellan spacecraft, with some gaps filled in by the Pioneer Venus orbiter. Credit: NASA/JPL
And due to its thick atmosphere and proximity to the Sun, it is the Solar Systems hottest planet, with temperatures reaching up to a scorching 735 K (462 °C). To put that in perspective, that’s over four and a half times the amount of heat needed to evaporate water, and about twice as much needed to turn tin into molten metal (231.9 °C)!

  • Diameter: 7,521 miles (12,104 km)
  • Mass: 4.867 x 1024 kg (0.815 Earth mass)
  • Length of Year (Orbit): 225 days
  • Length of day: 243 Earth days
  • Surface temperature: 462 degrees C (864 degrees F)
  • Venus’ thick and toxic atmosphere is made up mostly of carbon dioxide (CO2) and nitrogen (N2), with clouds of sulfuric acid (H2SO4) droplets.
  • Venus has no moons.
  • Venus spins backwards (retrograde rotation), compared to the other planets. This means that the sun rises in the west and sets in the east on Venus.
  • If you weigh 45 kg (100 pounds) on Earth, you would weigh 41 kg (91 pounds) on Venus.
  • Venus is also known and the “morning star” or “evening star” because it is often brighter than any other object in the sky and is usually seen either at dawn or at dusk. Since it is so bright, it has often been mistaken for a UFO!
  • More than 40 spacecraft have explored Venus. The Magellan mission in the early 1990s mapped 98 percent of the planet’s surface. Find out more about all the missions here.
  • Find out more about Venus on this article from Universe Today, and this page from NASA.
Earth:Our home, and the only planet in our Solar System (that we know of) that actively supports life. Our planet is the third from the our Sun, orbiting it at an average distance of 150 million km (93 million miles) from the Sun, or one AU. Given the fact that Earth is where we originated, and has all the necessary prerequisites for supporting life, it should come as no surprise that it is the metric on which all others planets are judged.



Full Earth from Apollo 17


Earth, pictured by the crew of the Apollo 17 mission. Credit: NASA
Whether it is gravity (g), distance (measured in AUs), diameter, mass, density or volume, the units are either expressed in terms of Earth’s own values (with Earth having a value of 1) or in terms of equivalencies – i.e. 0.89 times the size of Earth. Here’s a rundown of the kinds of

  • Diameter: 12,760 km (7,926 miles)
  • Mass: 5.97 x 1024 kg
  • Length of Year (Orbit): 365 days
  • Length of day: 24 hours (more precisely, 23 hours, 56 minutes and 4 seconds.)
  • Surface temperature: Average is about 14 C, (57 F), with ranges from -88 to 58 (min/max) C (-126 to 136 F).
  • Earth is another terrestrial planet with an ever-changing surface, and 70 percent of the Earth’s surface is covered in oceans.
  • Earth has one moon.
  • Earth’s atmosphere is 78% nitrogen, 21% oxygen, and 1% various other gases.
  • Earth is the only world known to harbor life.
  • Find out more about Earth at a series of articles found here on Universe Today, and on this webpage from NASA.
Mars:Mars is the fourth planet from the sun at a distance of about 228 million km (142 million miles) or 1.52 AU. It is also known as “the Red Planet” because of its reddish hue, which is due to the prevalence of iron oxide on its surface. In many ways, Mars is similar to Earth, which can be seen from its similar rotational period and tilt, which in turn produce seasonal cycles that are comparable to our own.



The Planet Mars. Image credit: NASA


Global image of the planet Mars. Credit: NASA
The same holds true for surface features. Like Earth, Mars has many familiar surface features, which include volcanoes, valleys, deserts, and polar ice caps. But beyond these, Mars and Earth have little in common. The Martian atmosphere is too thin and the planet too far from our Sun to sustain warm temperatures, which average 210 K (-63 ºC) and fluctuate considerably.

  • Diameter: 6,787 km, (4,217 miles)
  • Mass: 6.4171 x 1023 kg (0.107 Earths)
  • Length of Year (Orbit): 687 Earth days.
  • Length of day: 24 hours 37 minutes.
  • Surface temperature: Average is about -55 C (-67 F), with ranges of -153 to +20 °C (-225 to +70 °F)
  • Mars is the fourth terrestrial planet in our Solar System. Its rocky surface has been altered by volcanoes, impacts, and atmospheric effects such as dust storms.
  • Mars has a thin atmosphere made up mostly of carbon dioxide (CO2), nitrogen (N2) and argon (Ar).If you weigh 45 kg (100 pounds) on Earth, you would weigh 17 kg (38 pounds) on Mars.
  • Mars has two small moons, Phobos and Deimos.
  • Mars is known as the Red Planet because iron minerals in the Martian soil oxidize, or rust, causing the soil to look red.
  • More than 40 spacecraft have been launched to Mars. You can find out more about missions to Mars here.Find out more about Mars at this series of articles on Universe Today, and at this NASA webpage.
Jupiter:Jupiter is the fifth planet from the Sun, at a distance of about 778 million km (484 million miles) or 5.2 AU. Jupiter is also the most massive planet in our Solar System, being 317 times the mass of Earth, and two and half times larger than all the other planets combined. It is a gas giant, meaning that it is primarily composed of hydrogen and helium, with swirling clouds and other trace gases.



Io and Jupiter as seen by New Horizons during its 2008 flyby. (Credit: NASA/Johns Hopkins University APL/SWRI).


Io and Jupiter as seen by New Horizons during its 2008 flyby. (Credit: NASA/Johns Hopkins University APL/SWRI).
Jupiter’s atmosphere is the most intense in the Solar System. In fact, the combination of incredibly high pressure and coriolis forces produces the most violent storms ever witnessed. Wind speeds of 100 m/s (360 km/h) are common and can reach as high as 620 km/h (385 mph). In addition, Jupiter experiences auroras that are both more intense than Earth’s, and which never stop.

  • Diameter: 428,400 km (88,730 miles)
  • Mass: 1.8986 × 1027 kg (317.8 Earths)
  • Length of Year (Orbit): 11.9 Earth years
  • Length of day: 9.8 Earth hours
  • Temperature: -148 C, (-234 F)
  • Jupiter has 67 known moons, with an additional 17 moons awaiting confirmation of their discovery – for a total of 67 moons. Jupiter is almost like a mini solar system!
  • Jupiter has a faint ring system, discovered in 1979 by the Voyager 1 mission.
  • If you weigh 45 kg (100 pounds) on Earth, you would weigh 115 kg (253) pounds on Jupiter.
  • Jupiter’s Great Red Spot is a gigantic storm (bigger than Earth) that has been raging for hundreds of years. However, it appears to be shrinking in recent years.
  • Many missions have visited Jupiter and its system of moons, with the latest being the Juno mission will arrive at Jupiter in 2016. You can find out more about missions to Jupiter here.
  • Find out more about Jupiter at this series of articles on Universe Today and on this webpage from NASA.


Saturn's relatively thin main rings are about 250,000 km (156,000 miles) in diameter. (Image: NASA/JPL-Caltech/SSI/J. Major)


Saturn’s relatively thin main rings are about 250,000 km (156,000 miles) in diameter. (Image: NASA/JPL-Caltech/SSI/J. Major)
Saturn:Saturn is the sixth planet from the Sun at a distance of about 1.4 billion km (886 million miles) or 9.5 AU. Like Jupiter, it is a gas giant, with layers of gaseous material surrounding a solid core. Saturn is most famous and most easily recognized for its spectacular ring system, which is made of seven rings with several gaps and divisions between them.

  • Diameter: 120,500 km (74,900 miles)
  • Mass: 5.6836 x 1026 kg (95.159 Earths)
  • Length of Year (Orbit): 29.5 Earth years
  • Length of day: 10.7 Earth hours
  • Temperature: -178 C (-288 F)
  • Saturn’s atmosphere is made up mostly of hydrogen (H2) and helium (He).
  • If you weigh 45 kg (100 pounds) on Earth, you would weigh about 48 kg (107 pounds) on Saturn
  • Saturn has 53 known moons with an additional 9 moons awaiting confirmation.
  • Five missions have gone to Saturn. Since 2004, Cassini has been exploring Saturn, its moons and rings. You can out more about missions to Saturn here.
  • Find out more about Saturn at this series of articles on Universe Today and at this webpage from NASA.
Uranus:Uranus is the seventh planet from the sun at a distance of about 2.9 billion km (1.8 billion miles) or 19.19 AU. Though it is classified as a “gas giant”, it is often referred to as an “ice giant” as well, owing to the presence of ammonia, methane, water and hydrocarbons in ice form. The presence of methane ice is also what gives it its bluish appearance.



Uranus as seen by NASA's Voyager 2. Credit: NASA/JPL


Uranus as seen by NASA’s Voyager 2 space probe. Credit: NASA/JPL
Uranus is also the coldest planet in our Solar System, making the term “ice” seem very appropriate! What’s more, its system of moons experience a very odd seasonal cycle, owing to the fact that they orbit Neptune’s equator, and Neptune orbits with its north pole facing directly towards the Sun. This causes all of its moons to experience 42 year periods of day and night.

  • Diameter: 51,120 km (31,763 miles)
  • Mass:
  • Length of Year (Orbit): 84 Earth years
  • Length of day: 18 Earth hours
  • Temperature: -216 C (-357 F)
  • Most of the planet’s mass is made up of a hot dense fluid of “icy” materials – water (H2O), methane (CH4). and ammonia (NH3) – above a small rocky core.
  • Uranus has an atmosphere which is mostly made up of hydrogen (H2) and helium (He), with a small amount of methane (CH4). The methane gives Uranus a blue-green tint.
  • If you weigh 45 kg (100 pounds) on Earth, you would weigh 41 kg (91 pounds) on Uranus.
  • Uranus has 27 moons.
  • Uranus has faint rings; the inner rings are narrow and dark and the outer rings are brightly colored.
  • Voyager 2 is the only spacecraft to have visited Uranus. Find out more about this mission here.
  • You can find out more about Uranus at this series of articles on Universe Today and this webpage from NASA.
Neptune: Neptune is the eighth and farthest planet from the Sun, at a distance of about 4.5 billion km (2.8 billion miles) or 30.07 AU. Like Jupiter, Saturn and Uranus, it is technically a gas giant, though it is more properly classified as an “ice giant” with Uranus.



Neptune photographed by Voyage. Image credit: NASA/JPL


Neptune photographed by the Voyager 2 space probe. Credit: NASA/JPL
Due to its extreme distance from our Sun, Neptune cannot be seen with the naked eye, and only one mission has ever flown close enough to get detailed images of it. Nevertheless, what we know about it indicates that it is similar in many respects to Uranus, consisting of gases, ices, methane ice (which gives its color), and has a series of moons and faint rings.

  • Diameter: 49,530 km (30,775 miles)
  • Mass: 1.0243 x 1026 kg (17 Earths)
  • Length of Year (Orbit): 165 Earth years
  • Length of day: 16 Earth hours
  • Temperature: -214 C (-353 F)
  • Neptune is mostly made of a very thick, very hot combination of water (H2O), ammonia (NH3), and methane (CH4) over a possible heavier, approximately Earth-sized, solid core.
  • Neptune’s atmosphere is made up mostly of hydrogen (H2), helium (He) and methane (CH4).
  • Neptune has 13 confirmed moons and 1 more awaiting official confirmation.
  • Neptune has six rings.
  • If you weigh 45 kg (100 pounds) on Earth, you would weigh 52 kg (114 pounds) on Neptune.
    Neptune was the first planet to be predicted to exist by using math.
  • Voyager 2 is the only spacecraft to have visited Neptune. You can find out more about this mission here.
  • Find out more about Neptune at this series of articles on Universe Today and this NASA webpage. We have written many articles about the planets for Universe Today. Here are some facts about planets, and here’s an article about the names of the planets.If you’d like more info on the Solar System planets, dwarf planets, asteroids and more, check out NASA’s Solar System exploration page, and here’s a link to NASA’s Solar System Simulator.We’ve also recorded a series of episodes of Astronomy Cast about every planet in the Solar System. Start here, Episode 49: Mercury.Venus is the second planet from the Sun, and it is the hottest planet in the Solar System due to its thick, toxic atmosphere which has been described as having a “runaway greenhouse effect” on the planet.


Now you know! And if you find yourself unable to remember all the planets in their proper order, just repeat the words, “My Very Educated Mother Just Served Us Noodles.” Of course, the Pie, Ham, Muffins and Eggs are optional, as are any additional courses that might be added in the coming years!

We have many great articles on the Solar System and the planets here at Universe Today. Here is a rundown of the Inner Planets, the Outer Planets, a description of Terrestrial Planets, the Dwarf Planets, and Why Pluto is no Longer a Planet?.

Astronomy Cast also has some cool episodes about the Solar System. Here’s Episode 68: Pluto and the Icy Outer Planets, Episode 306: Accretion Discs, and Episode 159: Planet X.





About 

Matt Williams is the Curator of the Guide to Space for Universe Today, a a regular contributor to HeroX, a science fiction author, and a Taekwon-Do instructor. He lives with his family on Vancouver Island in beautiful BC.

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Thursday, April 16, 2015

TRIFIDI NEBULA ACROSS THE UNIVERSE

TRIFIDI NEBULA ACROSS THE UNIVERSE :

TRIFIDI NEBULA ACROSS THE UNIVERSE
TRIFIDI NEBULA ACROSS THE UNIVERSE

In the Center of the Trifid Nebula

In the Center of the Trifid Nebula: APOD: 2013 January 28 - In the Center of the Trifid Nebula


Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2013 January 28


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: Clouds of glowing gas mingle with dust lanes in the Trifid Nebula, a star forming region toward the constellation of the Archer (Sagittarius). In the center, the three prominent dust lanes that give the Trifid its name all come together. Mountains of opaque dust appear on the right, while other dark filaments of dust are visible threaded throughout the nebula. A single massive star visible near the center causes much of the Trifid's glow. The Trifid, also known as M20, is only about 300,000 years old, making it among the youngest emission nebulae known. The nebula lies about 9,000 light years away and the part pictured here spans about 10 light years. The above image is a composite with luminance taken from an image by the 8.2-m ground-based Subaru Telescope, detail provided by the 2.4-m orbiting Hubble Space Telescope, color data provided by Martin Pugh and image assembly and processing provided by Robert Gendler.

NGC 4372 and the Dark Doodad

NGC 4372 and the Dark Doodad: APOD: 2013 January 31 - NGC 4372 and the Dark Doodad


Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2013 January 31
See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: The delightful Dark Doodad Nebula drifts through southern skies, a tantalizing target for binoculars in the constellation Musca, The Fly. The dusty cosmic cloud is seen against rich starfields just south of the prominent Coalsack Nebula and the Southern Cross. Stretching for about 3 degrees across this scene the Dark Doodad seems punctuated at its southern tip (lower left) by globular star cluster NGC 4372. Of course NGC 4372 roams the halo of our Milky Way Galaxy, a background object some 20,000 light-years away and only by chance along our line-of-sight to the Dark Doodad. The Dark Doodad's well defined silhouette belongs to the Musca molecular cloud, but its better known alliterative moniker was first coined by astro-imager and writer Dennis di Cicco in 1986 while observing comet Halley from the Australian outback. The Dark Doodad is around 700 light-years distant and over 30 light-years long.

Atlas V Launches TDRS-K

Atlas V Launches TDRS-K: APOD: 2013 February 1 - Atlas V Launches TDRS-K


Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2013 February 1


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: Beyond a fertile field of satellite communication antennas at Kennedy Space Center, an Atlas V rocket streaks into orbit in this long exposure photograph. In the thoughtfully composed image recorded on the evening of January 30, the antennas in the foreground bring to mind the rocket's payload, a Tracking and Data Relay Satellite (TDRS; sounds like TEE-dress). This TDRS-K is the first in a next-generation series adding to the constellation of NASA's communication satellites. Operating from geosynchronous orbit 22,300 miles (36,000 kilometers) above planet Earth, the network of TDRS satellites relays communications, data, and commands between spacecraft and ground stations. Formerly the TDRS network provided communications for space shuttle missions. In fact, many TDRS satellites were ferried as far as low Earth orbit on space shuttles. The TDRS network continues to support major spacecraft like the International Space Station, the Hubble Space Telescope, and the Fermi Gamma-ray Space Telescope.

Herschel's Andromeda

Herschel's Andromeda: APOD: 2013 February 2 - Herschel's Andromeda


Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2013 February 2


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: This infrared view from the Herschel Space Observatory explores the Andromeda Galaxy, the closest large spiral galaxy to our own Milky Way. Only 2.5 million light-years distant, the famous island universe is also known to astronomers as M31. Andromeda spans over 200,000 light-years making it more than twice the size of the Milky Way. Shown in false color, the image data reveal the cool dust lanes and clouds that still shine in the infrared but are otherwise dark and opaque at visual wavelengths. Red hues near the galaxy's outskirts represent the glow of dust heated by starlight to a few tens of degrees above absolute zero. Blue colors correspond to hotter dust warmed by stars in the more crowded central core. Also a tracer of molecular gas, the dust highlights Andromeda's prodigious reservoir of raw material for future star formation.

The Arms of M106

The Arms of M106: APOD: 2013 February 6 - The Arms of M106


Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2013 February 6


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: The spiral arms of bright galaxy M106 sprawl through this remarkable multiframe portrait, composed of data from ground- and space-based telescopes. Also known as NGC 4258, M106 can be found toward the northern constellation Canes Venatici. The well-measured distance to M106 is 23.5 million light-years, making this cosmic scene about 80,000 light-years across. Typical in grand spiral galaxies, dark dust lanes, youthful blue star clusters, and pinkish star forming regions trace spiral arms that converge on the bright nucleus of older yellowish stars. But this detailed composite reveals hints of two anomalous arms that don't align with the more familiar tracers. Seen here in red hues, sweeping filaments of glowing hydrogen gas seem to rise from the central region of M106, evidence of energetic jets of material blasting into the galaxy's disk. The jets are likely powered by matter falling into a massive central black hole.

Comet Lemmon near the South Celestial Pole

Comet Lemmon near the South Celestial Pole: APOD: 2013 February 7 - Comet Lemmon near the South Celestial Pole


Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2013 February 7


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: Currently sweeping through southern skies, Comet Lemmon (C/2012 F6) was named for its discovery last year as part of the Mount Lemmon (Arizona) Survey. Brighter than expected but still just below naked-eye visibility, Comet Lemmon sports a stunning lime green coma and faint divided tail in this telescopic image from February 4. The greenish tint comes from the coma's diatomic C2 gas fluorescing in sunlight. Captured from an observatory near Sydney, Australia, the color composite is constructed from a series of individual exposures registered on the comet. Across the 1 degree wide field of view, the star trails are a consequence of the comet's relatively rapid motion against the background of stars near the South Celestial Pole. Moving north, the comet should grow brighter, reaching a peak (3rd magnitude or so) when it is closest to the Sun in late March. By early April it should be visible from the northern hemisphere. Of course, this year Comet Lemmon may be just another pretty comet as skygazers on planet Earth also eagerly anticipate views of Comet PANSTARRS and Comet ISON.

NGC 6822: Barnard's Galaxy

NGC 6822: Barnard's Galaxy: APOD: 2013 February 8 - NGC 6822: Barnard's Galaxy


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2013 February 8


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: Grand spiral galaxies often seem to get all the glory, flaunting their young, bright, blue star clusters in beautiful, symmetric spiral arms. But small galaxies form stars too, like nearby NGC 6822, also known as Barnard's Galaxy. Beyond the rich starfields in the constellation Sagittarius, NGC 6822 is a mere 1.5 million light-years away, a member of our Local Group of galaxies. About 7,000 light-years across, the dwarf irregular galaxy is seen to be filled with young blue stars and mottled with the telltale pinkish hydrogen glow of star forming regions in the deep color composite image. Contributing to the science of LITTLE THINGS, this portrait of a small galaxy was made as part of the Lowell Amateur Research Initiative (LARI), welcoming collaborations with amateur astronomers.

Asteroids in the Distance

Asteroids in the Distance: APOD: 2013 February 10 - Asteroids in the Distance


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2013 February 10


See Explanation. Clicking on the picture will download the highest resolution version available.
Asteroids in the Distance

Image Credit: R. Evans & K. Stapelfeldt (JPL), WFPC2, HST, NASA
Explanation: Rocks from space hit Earth every day. The larger the rock, though, the less often Earth is struck. Many kilograms of space dust pitter to Earth daily. Larger bits appear initially as a bright meteor. Baseball-sized rocks and ice-balls streak through our atmosphere daily, most evaporating quickly to nothing. Significant threats do exist for rocks near 100 meters in diameter, which strike the Earth roughly every 1000 years. An object this size could cause significant tsunamis were it to strike an ocean, potentially devastating even distant shores. A collision with a massive asteroid, over 1 km across, is more rare, occurring typically millions of years apart, but could have truly global consequences. Many asteroids remain undiscovered. In fact, one was discovered in 1998 as the long blue streak in the above archival image taken by the Hubble Space Telescope. Further, just last year the 50-meter wide asteroid 2012 DA14 was discovered that will pass inside the orbit of Earth's geosynchronous satellites this coming Friday. A collision with a large asteroid would not affect Earth's orbit so much as raise dust that would affect Earth's climate. One likely result is a global extinction of many species of life, possibly dwarfing the ongoing extinction occurring now.

N11: Star Clouds of the LMC

N11: Star Clouds of the LMC:

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2013 February 11


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Explanation: Massive stars, abrasive winds, mountains of dust, and energetic light sculpt one of the largest and most picturesque regions of star formation in the Local Group of Galaxies. Known as N11, the region is visible on the upper right of many images of its home galaxy, the Milky Way neighbor known as the Large Magellanic Clouds (LMC). The above image was taken for scientific purposes by the Hubble Space Telescope and reprocessed for artistry by an amateur to win the Hubble's Hidden Treasures competition. Although the section imaged above is known as NGC 1763, the entire N11 emission nebula is second in LMC size only to 30 Doradus. Studying the stars in N11 has shown that it actually houses three successive generations of star formation. Compact globules of dark dust housing emerging young stars are also visible around the image.

Shadows Across Jupiter

Shadows Across Jupiter: APOD: 2013 February 15 - Shadows Across Jupiter


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2013 February 15


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Explanation: Two dark shadows loom across the banded and mottled cloud tops of Jupiter in this sharp telescopic view. In fact, captured on January 3rd, about a month after the ruling gas giant appeared at opposition in planet Earth's sky, the scene includes the shadow casters. Visible in remarkable detail at the left are the large Galilean moons Ganymede (top) and Io. With the two moon shadows still in transit, Jupiter's rapid rotation has almost carried its famous Great Red Spot (GRS) around the planet's limb from the right. The pale GRS was preceded by the smaller but similar hued Oval BA, dubbed Red Spot Jr., near top center. North is down in the inverted image.

M51: The Whirlpool Galaxy in Dust and Stars

M51: The Whirlpool Galaxy in Dust and Stars: APOD: 2013 February 24 - M51: The Whirlpool Galaxy in Dust and Stars





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Each day a different image or photograph of our fascinating universe is
featured, along with a brief explanation written by a professional astronomer.


2013 February 24


See Explanation.  Clicking on the picture will download 
the highest resolution version available.


M51: The Whirlpool Galaxy in Dust and Stars
Image Credit: N. Scoville
(Caltech), T. Rector
(U. Alaska, NOAO)
et al., Hubble Heritage Team,
NASA
Explanation:
The Whirlpool Galaxy is a classic spiral galaxy.

At only 30 million
light years distant and fully 60 thousand light years across,
M51, also known as

NGC 5194, is one of the brightest and most
picturesque galaxies on the sky.

The above
image
is a digital combination of a ground-based image from the
0.9-meter telescope at
Kitt Peak National Observatory
and a space-based image from the
Hubble Space Telescope highlighting sharp features normally too red to be seen.

Anyone with a good pair of
binoculars, however, can see this
Whirlpool toward the constellation of the Hunting Dogs
(Canes Venatici.

M51 is a
spiral galaxy of type Sc
and is the dominant member of a
whole group of galaxies.

Astronomers speculate that M51's
spiral structure is primarily due to its
gravitational interaction with a
smaller galaxy
just off the top of the image.





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Fly Me to the Moons

Fly Me to the Moons: APOD: 2013 February 25 - Fly Me to the Moons


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2013 February 25


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Explanation: Sometimes the Moon is a busy direction. Last week, for example, our very Moon passed in front of the planet Jupiter. While capturing this unusual spectacle from New South Wales, Australia, a quick-thinking astrophotographer realized that a nearby plane might itself pass in front of the Moon, and so quickly reset his camera to take a continuous series of short duration shots. As hoped, for a brief instant, that airplane, the Moon, and Jupiter were all visible in a single exposure, which is shown above. But the project was not complete -- a longer exposure was then taken to bring up three of the Jupiter's own moons: Io, Calisto, and Europa (from left to right). Unfortunately, this triple spectacle soon disappeared. Less than a second later, the plane flew away from the Moon. A few seconds after that, the Moon moved to cover all of Jupiter. A few minutes after that, Jupiter reappeared on the other side of the Moon, and even a few minutes after that the Moon moved completely away from Jupiter. Although hard to catch, planes cross in front of the Moon quite frequently, but the Moon won't eclipse Jupiter again for another three years.

Colors of Mercury

Colors of Mercury: APOD: 2013 March 1 - Colors of Mercury


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2013 March 1


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Explanation: The colors of the solar system's innermost planet are enhanced in this tantalizing view, based on global image data from the Mercury-orbiting MESSENGER spacecraft. Human eyes would not discern the clear color differences but they are real none the less, indicating distinct chemical, mineralogical, and physical regions across the cratered surface. Notable at the upper right, Mercury's large, circular, tan colored feature known as the Caloris basin was created by an impacting comet or asteroid during the solar system's early years. The ancient basin was subsequently flooded with lava from volcanic activity, analogous to the formation of the lunar maria. Color contrasts also make the light blue and white young crater rays, material blasted out by recent impacts, easy to follow as they extend across a darker blue, low reflectance terrain.