Feb. 6, 2009 -- Beauty aside, what is most striking about NGC 4921, a spiral galaxy located about 350 million light years from Earth, is why it lives in a neighborhood populated mostly by elliptically-shaped neighbors. Located in the crowded Coma cluster in the constellation Coma Berenices, NGC 4921 bears little resemblance to spiral galaxies like our own Milky Way. In place of sweeping arms, bursting with new stars, NGC 4921 has just a delicate swirl of dust. The galaxy appears smooth and somewhat translucent. Astronomers suspect NGC 4921 has been interacting with its neighbors -- and steadily losing ground. "It seems clearer and clearer now that this suspicion, which has actually been around for decades and decades, that galaxies evolve by colliding and merging is true," said Lars Lindberg Christensen, an astronomer with the European Space Agency's Hubble project in Garching, Germany, which released the image on Thursday. Related Content: "Often gas-rich spiral galaxies form larger elliptical galaxies that are devoid of gas," he said. "When we see them now, they've been dormant for a long time." NGC 4921 appears to be a galaxy in transition. "We see a galaxy that is in a very dense environment ... where lots of galaxies can perturb it, bump into it, merge with it," Christensen told Discovery News. The collisions turn gas-rich spiral galaxies, like NGC 4921 into elliptically shaped structures without much star formation. Astronomers believe that's why the densely packed Coma Cluster has so many elliptical galaxies compared to spirals. "There's evidence that spirals were born before ellipticals," said Charles Demer, a theorist with the Naval Research Laboratory. "When we look at clusters like Coma, it's as if the spirals go away and the ellipticals appear." Get More NewsSpiders, Scorpions Among World's Oldest CreaturesMany creepy crawlies have been on Earth much longer than previously believed.Blood-Sucking Vampire Bats Sing DuetsWhite-winged vampire bats "harmonize" with separated roost mates.Oldest Hebrew Writing Possibly FoundAncient inscriptions on a 3,000-year-old pottery shard could make history.Rare, Prehistoric-Age Reptile Found in N.Z.A tuatara has been spotted on the New Zealand mainland for the first time in 200 years.Iceman Has No Living RelativesOetzi, the 5,300 year-old frozen mummy, left no living genetic legacy.SLIDE SHOW: Landscapes of TerrorWhat makes a place feel scary? There are scientific explanations.It's Official: People Are Warming the PolesHumans are conclusively to blame for polar warming, say scientists.Eight-Armed Animal Preceded DinosaursWhat may be one of Earth's first animals was no bigger than a coaster and had eight arms.Phoenicians Live on in People's GenesOne in 17 Mediterranean men may be descended from ancient Phoenicians.Pesticides, Fertilizers Linked to Frog DeclineA pesticide is found to promote parasites among amphibians.Hubble Telescope Taking Photos AgainThe Hubble Space Telescope is once again snapping stunning photos of the universe.Andean Mummy Hairs Show Hallucinogen UseScientists find direct evidence of hallucinogenic drug use among ancient Andeans.Opals on Mars Reveal Planet's Long Wet PastOpals found on Mars suggest the planet has been wet for much longer. |
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