Europa, which holds twice as much water as all of Earth's oceans combined, is primed to support life.
NASA, ESA, and Q.D. Wang (University of Massa
The Hubble Space Telescope has dazzled us for years with its unbelievable images of breathtaking cosmic phenomena. In honor of its 20th anniversary in orbit, we're sharing what we think are some of Hubble’s best photos. This composite color infrared image is a sweeping panorama of our galactic home – the Milky Way. Along with the Spitzer Space Telescope, Hubble captured the core of our galaxy, which hosts massive star clusters and gassy bodies. Astronomers have used this image, created from several shots collected between Feb. 22 and June 5, 2008, to track how stars react to changing environments.
NASA, ESA, and S. Beckwith (STScI) and the HU
Ultra Deep Field
Using its new Wide Field Camera 3, installed in May 2009, Hubble was able to photograph some of the universe’s oldest galaxies, several dating back to the “dark ages,” shortly after the Big Bang. Scientists who studied the images said the galaxies were “likely to be the most distant ever seen." The Ultra Dark Field is estimated to hold over 10,000 galaxies.
NASA, ESA, J. Hester and A. Loll (Arizona Sta
This spindly mass of blue and yellow is all that remains of a once gigantic supernova. Spanning 10 light-years across, the Crab Nebula has a neutron star as massive as the sun in its center that rotates about 30 times a second. Although this image was taken in 2008, astronomers have known about NGC 1952 for centuries. It was first recorded nearly 1,000 years ago by Chinese and Japanese observers in 1054.
NASA, ESA, and the Hubble SM4 ERO Team
What may look like an image of a delicate butterfly is actually a snapshot of incredible chaos in a dramatic death scene. The star at the center of the Butterfly Nebula, NGC 6302, is dying, causing huge outbursts of gas and dust to rush out at over 600,000 miles per hour, shown here in what looks like wings. It’s estimated that the star’s surface temperature is 250,000 degrees Celsius (450,032 degrees Fahrenheit). Hubble captured this new, detailed image in 2009.
J.P. Harrington and K.J. Borkowski (U. Maryla
Cat's Eye Nebula
One of the first planetary nebulae discovered, the Cat’s Eye Nebula, has one of the most complex nebula forms known to date. Although classified as a planetary nebula, the Cat’s Eye Nebula is actually a binary star system. This 2002 infrared image shows a dying star throwing off 11 gaseous rings, giving it an eerie glow.
NASA, H. Ford (JHU), G. Illingworth (UCSC/LO)
Weird, swollen shapes that look like a sea monster make up the Cone Nebula, named for its obvious conical shape. This Hubble image, captured in 2002, shows only the top 2.4 light-years of the nebula, a height that equals 23 million round trips to the moon. As radiation from hot, young stars eat away at the nebula, the edges of the dark cloud release more hydrogen gas, building up the pillar forms. It’s possible that over time, the densest parts of the nebula could house planets and stars.
NASA, ESA, STScI, J. Hester and P. Scowen (Ar
Hubble took this photo of towering evaporating gaseous globules (EGGs) found inside the Eagle Nebula in 1995. These giant pillars of hydrogen gas and dust are light years in height and are so dense that they form a gravitational pull strong enough to snatch up stars.
NASA, ESA, T. Megeath (University of Toledo)
In the most detailed image ever shot of the misty Orion Nebula, Hubble captured a rare opportunity for astronomers to study star evolution. M42 is a large star-forming region near Earth, and the nebula’s several active stars have blown away gas and dust clouds that would otherwise block the view of the nebula, astronomers say. Shot in 2009, this image allows astronomers to track ongoing stages of star birth, growth and death. It’s estimated about 3,000 stars are hiding within Orion’s mist.
NASA and The Hubble Heritage Team (AURA/STScI
Black Eye Galaxy
What looks like a puffy black eye, the spiral galaxy M64, also known as the “Black Eye” or “Evil Eye” galaxy, earned its name from the swirling black dust clouds surrounding its center full of stars. Observations have determined that this galaxy is actually two counter-rotating systems, and likely formed when two separate galaxies collided, then merged. Even though M64 is 17 million light-years away from Earth, amateur astronomers have been able find it with their telescopes and it was first spotted in the 18th century. Hubble snapped this image in 2007.
NASA and The Hubble Heritage Team (AURA/STScI
Star V838 Monocerotis
This vibrant red supergiant lies near the edge of our Milky Way, about 20,000 light-years away from the sun. Its sudden outburst was first detected in January 2002, but Hubble captured this image in 2006. V838 Monocerotis’s shell, made up of dust, is about 14 light-years across. The starburst’s strange spherical shape continues to puzzle astronomers; where it fits into the timeline of star evolution and the cause of its outburst remain a mystery.
NASA, ESA, C.R. O'Dell (Vanderbilt University
Astronomers believe that our sun could look very much like this one day. The Helix Nebula, NGC 7293, a planetary nebula, is shown here very close to the end of its life as a sun-like star. The haze is the star’s outer gases being expelled into space, leaving behind a white dwarf star. Spanning 2.5 light-years, Hubble took this image in 2009.
M. Wong and I. de Pater (University of Califo
Storms on Jupiter
For more than 300 years, Jupiter’s gaseous atmosphere has hosted a gigantic storm known has the Giant Red Spot. Then in 2006, another red storm appeared and produced what appeared to be a few other whitish storm spots. When Hubble snapped this image in 2008, astronomers were surprised to discover that a third red storm spot had appeared. They speculate that this storm outbreak is due to a large climate shift on Jupiter. What's being sucked up into these storms or what causes them is still unknown.
NASA, ESA, and Jonathan Nichols (University o
Saturn's Double Aurora Show
No, you’re not seeing double. Hubble caught Saturn putting on a double aurora show in 2008. The Cassini missions later captured the phenomenon in greater detail, but this Hubble image still shows the ultraviolet aurora on the ringed planet’s poles quite clearly. The double aurora are caused by solar wind sweeping over and around the planet, then interacting with particles in Saturn’s atmosphere, exactly how aurora on Earth are formed.
NASA/JPL-Caltech and The Hubble Heritage Team
This massive, dark, floating ring of dust particles casted out wide from its center is how the Sombrero Galaxy, M104, earned its name. Superimposed on this 2007 false-color infrared Hubble image, M104 casts off a brilliant glow from the black hole astronomers suspect lies in its center: A black hole a billion times the mass of our sun, that is.
What may look like a quiet meeting is actually a scene of galactic wreckage. The famous galaxy grouping, known as Stephen’s Quintet, shows three of the galaxies have distorted shapes -- proof of a close encounter at one time. The interactions of the three have sparked a star birth boom in the center pair of galaxies. Taken in 2009, the visible and infrared light image shows galaxy NGC 7319 at the top. Continuing clockwise, what looks like a galaxy with two cores is two separate bodies, NGC 7318A and NGC 7318B. Bottom left lies NGC 7313, a relatively normal looking elliptical galaxy, and finally, the dwarf galaxy NGC 7320 appears in the upper left.
NASA, ESA, S. Beckwith (STScI), and The Hubbl
This swirling mass of what looks like two galaxies holding hands is made up of a well-defined spiral galaxy, NGC 5195, and its smaller companion, NGC 5195. Although both look fuzzy, each galaxy is an extremely complex structure, captured by Hubble in 2009. The larger Whirlpool Galaxy is one of the brightest in the universe and the end of its arm is actually blocking the view of the smaller one as it’s reeling it in.
European Space Agency, NASA, E. Olszewski (U
Star Cluster NGC 290
These sparkling gems are actually just a small snippet of the stellar brilliance within the star cluster NGC 290. It’s located in the Small Magellanic Cloud, about 200,000 light-years away from Earth. Held together by gravity, star clusters can crowd in hundreds of thousands of stars. Stars in these globular clusters are usually relatively young and can exist for many billions of years. This image of NGC 290 was taken in 2008.
NASA, ESA, N. Smith (University of California
This panorama image brilliantly shows off a nebula lying in one of the brightest parts of the Milky Way. The Giant Nebula in Carina, NGC 3372, houses several massive stars and constantly changing nebulae, the most energetic being Eta Carina. The impressive nebula spans over 300 light-years and houses billions of stars. Hubble shot this controlled colored image in 2009 and it was the most detailed one of the Carina Nebula ever taken before NASA released this Hubble shot of Carina's "mystic mountain." Happy birthday, Hubble!
Jupiter's moon Europa should have enough oxygen-rich water to support not only simple micro-organisms but also complex life, according to a University of Arizona researcher who studies ice flows on the frozen moon.
Judging by how quickly Europa's surface ice is replenished, Richard Greenberg estimates that enough oxygen reaches the subterranean ocean to sustain "macrofauna" — more complex, animal-like organisms.
Assuming Europa life forms would need as much oxygen as Earth-like fish, Greenberg estimates the moon's ocean has enough oxygen to support 6.6 billion pounds of macrofauna.
A key question about whether Europa can support life has been whether its suspected buried ocean contains adequate levels of oxygen.
Although scientists have found life on Earth around deep-ocean vents and hot springs that use sulfur or methane-based chemistry, it is unknown whether Europa's ocean floor sports similar features.
Greenberg believes oxygen in Europa's ocean can arrive from energetic particles from the sun, despite the fact that the ocean is buried beneath a thick layer of ice. Analysis of Europa's surface, which is unusually smooth and crater-free compared to other bodies in the solar system, suggests that the top layer of ice is relatively young, just 50 million years old or so.
Greenberg outlines three possibilities for Europa's resurfacing: fresh material layers on top, opening cracks in the ice that fill with new material, and/or patches of ice that are disturbed and replaced with fresh material.
Based on estimates for the production of oxidizers at the surface, Greenberg says oxygen buildup in Europa's ocean is happening so quickly that it could exceed that of the Earth's oceans in a few million years.
"We do not have definitive evidence for the existence of a liquid ocean, but the information we do have is compelling," Arizona State University planetary geologist Ronald Greeley told Discovery News.
"If there is evidence for oxygenation, then the presence of oxygen would certainly increase the environmental conditions for life. It doesn't mean life is there," he added, " just that there might be free oxygen available to support biological processes."
Greenberg is scheduled to present his findings at the American Astronomical Society's Division for Planetary Sciences in Puerto Rico on Friday.