Hubble Celebrates Its Anniversary with a Spectacular Pair of Galaxies
When the Hubble Space Telescope launched aboard the Space Shuttle Discovery on April 24, 1990, astronomers could only dream what they might see. Now, 27 years and more than a million observations later, the telescope delivers yet another magnificent view of the universe — this time, a striking pair of spiral galaxies much like our own Milky Way. These island cities of stars, which are approximately 55 million light-years away, give astronomers an idea of what our own galaxy would look like to an outside observer. The edge-on galaxy is called NGC 4302, and the tilted galaxy is NGC 4298. Although the pinwheel galaxies look quite different because they are angled at different positions on the sky, they are actually very similar in terms of their structure and contents.
Best Evidence Yet for Reoccurring Water Vapor Plumes Erupting from Jupiter’s Moon
When Galileo discovered Jupiter's moon Europa in 1610, along with three other satellites whirling around the giant planet, he could have barely imagined it was such a world of wonder.
This revelation didn't happen until 1979, when NASA's Voyager 1 and 2 flew by Jupiter and found evidence that Europa's interior, encapsulated under a crust of ice, has been kept warm over billions of years. The warmer temperature is due to gravitational tidal forces that flex the moon's interior — like squeezing a rubber ball — keeping it warm. At the time, one mission scientist even speculated that the Voyagers might catch a snapshot of geysers on Europa.
Such activity turned out to be so elusive that astronomers had to wait over three decades for the peering eye of Hubble to monitor the moon for signs of venting activity. A newly discovered plume seen towering 62 miles above the surface in 2016 is at precisely the same location as a similar plume seen on the moon two years earlier by Hubble. These observations bolster evidence that the plumes are a real phenomenon, flaring up intermittently in the same region on the satellite.
The location of the plumes corresponds to the position of an unusually warm spot on the moon's icy crust, as measured in the late 1990s by NASA's Galileo spacecraft. Researchers speculate that this might be circumstantial evidence for material venting from the moon's subsurface. The material could be associated with the global ocean that is believed to be present beneath the frozen crust. The plumes offer an opportunity to sample what might be in the ocean, in the search for life on that distant moon.
Majestic Giant Planet is a Swirl of Colorful Clouds
Named after the Roman king of the gods, the immense planet Jupiter is undoubtedly king of the solar system. Containing more mass than all the other planets combined, Jupiter's immense gravitational field deflects wayward comets that otherwise might slam into Earth, wreaking havoc.
This dazzling Hubble Space Telescope photo of Jupiter was taken when it was comparatively close to Earth, at a distance of 415 million miles. Hubble reveals the intricate, detailed beauty of Jupiter's clouds as arranged into bands of different latitudes, known as tropical regions. These bands are produced by air flowing in different directions at various latitudes. Lighter colored areas, called zones, are high-pressure where the atmosphere rises. Darker low-pressure regions where air falls are called belts. The planet's trademark, the Great Red Spot, is a long-lived storm roughly the diameter of Earth. Much smaller storms appear as white or brown-colored ovals. Such storms can last as little as a few hours or stretch on for centuries.
Star might answer question of how white dwarfs explode
Of all the varieties of exploding stars, the ones called Type Ia are perhaps the most intriguing. Their predictable brightness lets astronomers measure the expansion of the universe, which led to the discovery of dark energy. Yet the cause of these supernovae remains a mystery. Do they happen when two white dwarf stars collide? Or does a single white dwarf gorge on gases stolen from a companion star until bursting?
If the second theory is true, the normal star should survive. Astronomers used NASA's Hubble Space Telescope to search the gauzy remains of a Type Ia supernova in a neighboring galaxy called the Large Magellanic Cloud. They found a sun-like star that showed signs of being associated with the supernova. Further investigations will be needed to learn if this star is truly the culprit behind a white dwarf's fiery demise.
Some of the world's most exciting, young scientists to help NASA explore mysteries of the cosmos
NASA has selected 28 Fellows for its prestigious Einstein, Hubble, and Sagan fellowships. Each post-doctoral fellowship provides three years of support to awardees to pursue independent research in astronomy and astrophysics. The new Fellows will begin their programs in the fall of 2017 at a host university or research center of their choosing in the United States.