Universe Update, January 2011
The third Thursday of every month, the Morrison Planetarium hosts “Universe Update” at the 7:30 and 8:30 planetarium shows during NightLife. I select my favorite astronomy stories from the past month, and I give a brief run-down of current discoveries while taking audiences on a guided tour of the Universe. AS you may or may not know, the planetarium sports a three-dimensional atlas of the Universe, so we can take you places virtually while talking about the latest astronomy news.
Many of this month’s stories come from the 217th meeting of the American Astronomical Society (AAS), which took place last week in Seattle.
Starting out with some local news, the AAS awarded the 2011 Henry Norris Russell Lectureship to Sandra Faber at the University of California, Santa Cruz. The award recognizes a lifetime of achievement in astronomy, and Faber’s accomplishments include mapping the large-scale structure of the Universe (something we inevitably talk about during “Universe Update”). She follows in the footsteps of four other UC Santa Cruz astronomers to receive this honor, so Northern California represents!
Before I leave the topic of the AAS meeting, however, I thought I’d also point to an image of the “poster graveyard” at the end of the conference. Where do great ideas go after they’ve been meticulously described and printed out? The floor of the convention center, evidently, and thence to the trash…
From here on out, I’ll start at Earth and work my way to cosmological distances, which mirrors the structure of the live presentation. So I’ll list the news stories in the same order—from closest to farthest from home.
First off, an upcoming NASA launch! The Glory satellite will soon launch from Vandenberg Air Force Base. The mission will increase our detailed understanding of aerosols, tiny particles suspended in our atmosphere. We can currently make global maps of some of the bulk properties of aerosols, but some tiny, suspended particles act differently from other tiny, suspended particles, so we need more specific data. And the Glory Mission will detect “subtle differences between the many different types of aerosols,” which can better inform our understanding of the role they play in Earth’s climate.
Also close to Earth, an unusual announcement from NASA’s Fermi team, announcing that the satellite (intended to capture gamma rays from the exotic, distant objects) has also spotted signals from thunderstorms hurling antimatter into space. An online video explains the phenomenon much more thoroughly than I’ll attempt, but basically, thunderstorms on Earth create electrons that can initiate reactions that send antimatter particles careening down magnetic field lines, until they react with the Fermi spacecraft itself to create gamma rays that it detects. Yowza. Never know what you’re going to find…
A little farther from home, a recent study of meteorites from carbon-rich asteroids confirms previous research that molecules in these asteroids shows an intriguing asymmetry—the same as we see in life on Earth! First, you have to know that some molecules come in “right-handed” and “left-handed” varieties, mirror images of one another. Life on Earth prefers left-handed molecules, and scientists have debated why one form should be preferred over another. As it turns out, that bias may come from space: the prevalence of left-handed molecules in these new samples suggests that Earth may have been seeded by unequal amounts of the mirror molecules.
On another asteroid front, astronomers have almost literally “pieced together” a puzzle about the unusual asteroid Vesta. Unlike other asteroids, Vesta’s insides are different from its outer layers (we call that “a differentiated inner structure,” much like Earth has an inner iron core and less dense outer layers). Researchers matched up what they knew about Vesta’s inner composition with the make-up of Near-Earth Asteroid 1999TA10. It’s a great match! So TA10 probably came from inside Vesta. And because it approaches close to Earth, it may be responsible for some meteorites with Vesta-like compositions that have struck Earth in the past.
Heading way out of the Solar System now, I have to mention the important discovery from NASA’s Kepler Mission: the first definitively rocky planet! I mentioned this in my Science Today post last week, but basically, Kepler has provided the first definitive evidence of a planet with a solid surface. Call it a human bias, but we kind of expect that life requires a solid surface to evolve, so this discovery holds some importance for our continuing quest to find an Earth-like planet orbiting another star. (The only drawback? The newly-discovered planet lies so close to its parent star that the surface probably reaches temperatures hot enough to melt iron.)
In another post from last week, I described the highly-complementary Planck and Herschel missions, but last night, I highlighted just one important discovery: Planck’s 10,000 “cold cores” that could conceal protostars just before they ignite! We continue to find snapshots of the incredibly complex process of star formation, and this strikes me as an important clue…
Do galaxies with with bigger dark matter halos have bigger supermassive black holes? It might seem reasonable (certainly many astronomers thought so), but a new study suggests that this is not the case. There seems to be no relation between the dark matter and the black holes… As if to underscore the point, another recent announcement proclaimed, “Surprise: Dwarf Galaxy Harbors Supermassive Black Hole!”
Ever hear of Hanny’s Voorwerp? In one of the most widely-known achievements of the crowd-sourcing astronomy project Galaxy Zoo, Dutch teacher Hanny van Arkel discovered an unusual green blob of something near a galaxy in the massive Sloan Digital Sky Survey (SDSS) dataset, and she referred to it as a “voorwerp,” which apparently means something along the lines of “object” or “thingie” in Dutch. The discovery set off a chain of events leading to a team of astronomers amassing a variety of observations to figure out what caused the phenomenon van Arkel observed. An online comic book even chronicles the story. As announced at the AAS meeting, the Hubble Space Telescope imaged Hanny’s Voorwerp in (surprise, surprise) unprecedented detail, confirming what others had begun to suspect: Hanny’s Voorwerp might be the light echo of a quasar that turned off! Basically, a supermassive black hole at the center of this distant galaxy may have belched a significant amount of electromagnetic radiation, lighting up a distant cloud of gas—glowing green, showing up in the SDSS imagery, and getting spotted by a young Dutch teacher fiddling with astronomy data in her spare time.
Finally, I’ll touch on a collective announcement from several NASA Telescopes working jointly together to map out the Most Distant Galaxy Cluster. That’s the headline of the story, but a more interesting point from my perspective? In these data from 12.6 billion years ago (remember that the Universe is “only” 13.7 billion years old), we already see evidence of chemical enrichment. This implies that an earlier generation of stars has already seeded the cosmos with elements heavier than hydrogen and helium. Not a huge surprise given current computer models of the early Universe, but an impressive confirmation nonetheless.