Showing posts with label astronomy. Show all posts
Showing posts with label astronomy. Show all posts

Thursday, December 31, 2015

Huge Asteroid Cruises Past Earth




Asteroid-1998-qe2

An asteroid wider than nine ocean liners sailed safely past Earth today (May 31), making its closest flyby of our planet for at least the next 200 years.


Asteroid 1998 QE2, which is about 1.7 miles (2.7 kilometers) wide, cruised within 3.6 million miles (5.8 million km) of Earth at 4:59 p.m. EDT (2059 GMT) today, then slipped silently off into the depths of space once again.


The huge space rock never posed any danger of hitting Earth on this pass, scientists say. Indeed, at its closest approach this afternoon, 1998 QE2 was still about 15 times farther away than the moon is from Earth.






But astronomers have been tracking the asteroid closely nonetheless, regarding the close encounter as an opportunity to learn more about 1998 QE2’s composition, structure and orbit.


They’ve trained two huge radio telescopes on the space rock — NASA’s 230-foot-wide (70 meters) Deep Space Network antenna at Goldstone, Calif., and the 1,000-foot (305 m) dish at Arecibo Observatory in Puerto Rico.


“It is tremendously exciting to see detailed images of this asteroid for the first time,” Lance Benner, principal investigator for the Goldstone radar observations at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., said in a statement earlier this month.


“With radar, we can transform an object from a point of light into a small world with its own unique set of characteristics,” Benner added. “In a real sense, radar imaging of near-Earth asteroids is a fundamental form of exploring a whole class of solar system objects.”


The observation campaign is set to run through June 9, but it has already transformed scientists’ understanding of 1998 QE2. Researchers announced Thursday (May 30), for example, that the asteroid is actually a binary system, in which a 2,000-foot (600 m) moon circles the much larger space rock.


Asteroid 1998 QE2 was discovered in August 1998 by astronomers working with MIT’s Lincoln Near Earth Asteroid Research program in New Mexico. The space rock is one of 10,000 or so near-Earth asteroids identified to date, but the total population of these close-flying objects is thought to exceed 1 million.


Scientists are working hard to find and track as many of these asteroids as they can, starting with the biggest and most dangerous ones. The good news is that they’ve spotted virtually all the mountain-size asteroids like 1998 QE2 that could threaten human civilization if they hit Earth, and none are on a collision course with Earth for the foreseeable future.


Many smaller but still hazardous objects remain undiscovered, however. For example, astronomers have catalogued less than 30 percent of the asteroids at least 330 feet (100 m) wide that are thought to come uncomfortably close to Earth at some point in their orbits. Such objects could destroy an area the size of a state if they slammed into Earth.


Image courtesy of NASA; Homepage image courtesy of NASA Goddard Photo and Video



This article originally published at Space.com
here


Read more: http://mashable.com/2013/05/31/asteroid-1998-qe2-2/




Huge Asteroid Cruises Past Earth

Asteroid, Asteroids, astronomy, nasa, space, U.S., US & World, world

Thursday, April 9, 2015

17 Nebula Shapes You Didn’t Know Existed




Eagles, butterflies, and rotten eggs, oh my!

1. Orion Nebula


Orion Nebula

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NASA / Via dvidshub.net

Ever wonder where stars are born? (And we don’t mean reality television.) A mere 1,500 light-years from us, the Orion Nebula — pictured using infrared, ultraviolet, and visible-light colors — is the nearest star factory. It has a heart of four monstrously massive stars, collectively called the Trapezium because of the shape they make.


2. Eagle Nebula


Eagle Nebula

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NASA / Via dvidshub.net

This majestic pillar is 9.5 light-years (or about 57 trillion miles) high. Stars spawn in clouds of cold hydrogen, not unlike your own birth.


View this image ›


NASA / Via dvidshub.net

Here’s another view. These pillars of hydrogen gas and dust are incubators for new stars and are 7,000 light-years away in the constellation Serpens.


3. Wizard Nebula


Wizard Nebula

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NASA/JPL-Caltech/UCLA / Via dvidshub.net

This star cluster is in the constellation Cepheus and is about 7,000 light-years from Earth in the Milky Way Galaxy. The technical name of the cluster is NGC 7380, but let’s just pretend it’s really sorcery.


4. Crab Nebula


Crab Nebula

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NASA, ESA, J. Hester, A. Loll (ASU) / Via dvidshub.net

This nebula spans about 10 light-years and is the result of a supernova, which is an explosion when a star reaches the end of its life.


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NASA / Via dvidshub.net

Here’s a close-up of the center, courtesy of the Hubble. Chinese astronomers spotted it in 1054 A.D., when its life ended and it exploded as a supernova. Now it houses a pulsar, a type of neutron star, that spins on its axis 30 times a second.


5. The Cat’s Eye Nebula


The Cat

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NASA / Via dvidshub.net

It’s watching you, waiting to knock something over when you’re not looking. This nebula is estimated to be 1,000 years old and is a visual “fossil record” of the evolution of a dying star.


6. Rosette Nebula


Rosette Nebula

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X-ray (NASA/CXC/SAO/J. Wang et al), Optical (DSS & NOAO/AURA/NSF/KPNO 0.9-m. Rector et al) / Via dvidshub.net

This star-formation regions, shown here in a composite image, is 5,000 light-years from Earth. All the stars in the middle are younger with the fainter clusters on either side.


7. Tarantula Nebula


Tarantula Nebula

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NASA/JPL-Caltech/UCLA / Via dvidshub.net

About 160,000 light-years from Earth, the Tarantula nebula was determined to be a violent explosion of a massive star. A star-forming region, it’s a dainty 1,900 light-years across.


8. Lagoon Nebula


Lagoon Nebula

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NASA / Via dvidshub.net

How much paint would you need to cover a canvas nearly three light-years wide? The Lagoon Nebula is a star-forming region in the constellation Sagittarius 5,000 light-years away.


View this image ›


NASA / Via dvidshub.net

Here’s another view. The Hubble revealed a pair of one-half light-year long interstellar “twisters,” which scientists suspect are a difference in temperature between the hot surface and cold interior of the clouds combined with the pressure of starlight. Godspeed with that tornado, Helen Hunt.


9.

View this image ›


NASA / Via dvidshub.net

“Trifid” means divided into three clefts or points. This nebula lives in the constellation Sagittarius and shows a nearby massive star tearing apart an ill-fated stellar nursery about 9,000 light-years from Earth. Think of the children!


View this image ›


dvidshub.net / Via NASA, ESA, and The Hubble Heritage Team

And here’s an image of its heart.


10. Black Widow Nebula


Black Widow Nebula

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NASA / Via dvidshub.net

Astronomers suspect that a large cloud of gas and dust condensed to create multiple clusters of massive star formation. The winds from these groups of large stars probably blew out into the direction of least resistance, forming a double bubble. The baby stars are the yellow specks where the two bubbles overlap.


11. Butterfly Nebula


Butterfly Nebula

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NASA, ESA, and the Hubble SM4 ERO Team / Via dvidshub.net

Far from delicate, the wings are actually cauldrons of gas heated to more than 36,000 degrees Fahrenheit that are racing across space at more than 600,000 miles an hour — fast enough to travel from Earth to the moon in 24 minutes!


A dying star that was about five times the mass of our Sun is at the very center (hidden from direct view because of gas) and is estimated to be about 400,000 degrees Fahrenheit — one of the hottest stars in our galaxy. This nebula is about 3,800 light-years away in the constellation Scorpius, and the butterfly spreads over two light-years.


12. Boomerang Nebula


Boomerang Nebula

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NASA, ESA and The Hubble Heritage Team / Via dvidshub.net

Astronomers called it the Boomerang Nebula in 1980 after observing it with a large ground-based telescope, but after seeing high-resolution Hubble images, “Bow Tie Nebula” might have been better. Fierce 500,000 kilometer-per-hour winds blowing cold gas away from the central dying star seem to have created the shape.


13. Rotten Egg Nebula


Rotten Egg Nebula

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NASA / Via dvidshub.net

It’s a good thing this guy, more eloquently known as the Calabash Nebula, is 5,000 light years from Earth because its sulfur content would smell like rotten eggs (if one could smell in space, of course).


14. Dumbbell Nebula


Dumbbell Nebula

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NASA and The Hubble Heritage Team / Via dvidshub.net

Named after its resemblance to a dumbbell, the nebula was discovered in 1764 by Charles Messier. It’s a stone’s toss away at 1,360 light-years (if god threw it) and stretches across four-and-a-half light-years.


15. Cone Nebula


Cone Nebula

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NASA, H. Ford (JHU), G. Illingworth (USCS/LO), M. Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA / Via dvidshub.net

This monster is actually a pillar of gas and dust and it lives in a turbulent star-forming region. The entire nebula is seven light-years long, but this image only shows two and a half.


16. Carina Nebula


Carina Nebula

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NASA, ESA, N. Smith (University of California, Berkeley), and the Hubble Heritage Team / Via dvidshub.net

About 7,500 light-years from us is the Carina Nebula, a mountain of cold hydrogen gas laced with dust — and another hotbed of newborn stars.


View this image ›


NASA, ESA, N. Smith (University of California, Berkeley), and the Hubble Heritage Team / Via dvidshub.net

This composite shows it at about 53 light-years wide.


17. Horsehead Nebula


Horsehead Nebula

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Robert Gendler/Stocktrek Images/Robert Gendler/Stocktrek Images

One of the most spectacular space sights is the Horsehead Nebula, part of a large, dark molecular cloud embedded in the Orion Nebula.


Read more: http://buzzfeed.com/kasiagalazka/nebula-shapes-you-didnt-know-existed




17 Nebula Shapes You Didn’t Know Existed

astronomy, nebula, nebula photos, space