How well do you know your galaxies?


Modern telescopes have presented astronomers with a problem: there are too many images of galaxies for scientists to classify every single one. But crowdsourcing has an answer. Since 2007, some astronomers have enlisted “citizen scientists” to do the heavy lifting through a project known as Galaxy Zoo. The original project was so successful, in fact, that a follow-up — called Galaxy Zoo 2 — started up in 2009 and ran for 14 months. The team behind it all (which comes from multiple universities around the world) has now publicly released the data from Zoo 2. In all, over 300,000 galaxies were organized by nearly 84,000 volunteers completed a total of over 16 million classifications.

How did it work? It’s pretty simple, really. Volunteers with no prior knowledge visited a website and were presented with an image of a galaxy. They then answered a series of questions about the visual form of the galaxy, like whether it had arms or a bulge. Images were analyzed by many volunteers — on average each was classified 44 times — allowing the team to ensure they were receiving acceptably accurate results.

Compiling data on galaxies using the same method employed by Yelp and Foursquare to figure out if restaurants take credit cards may seem amateur, but the researchers say that computers are not yet able to match the human eye in identifying the physical form of galaxies, and the data they’ve received has proven accurate. If you want to get involved, the team is now working through imagery provided by Hubble of some of the most distant galaxies yet.


The voyage continues…


Space­craft Voy­ager 1 has officially entered inter­stel­lar space, although exact­ly when it left the helios­phere is still up for debate.m“This is the first man­made object that has left our home—our bub­ble—ever,” says Merav Opher, as­so­ciate pro­fes­sor of astron­o­my at Boston Uni­ver­si­ty and a guest inves­ti­ga­tor on NASA’s Voy­ager team. “Voy­ager is like our scout, telling us what lies beyond our home.”

NASA’s recent announce­ment, based on a new study pub­lished in the jour­nal Sci­ence, fol­lows a debate among some astronomers as to when or even whether the tran­sit beyond the heliopause had occurred. The Sci­ence study places the tran­sit as com­plet­ed on August 25, 2012.

One AU is the dis­tance from the sun to the Earth, which is about 93 mil­lion miles or 150 mil­lion kilo­me­ters. Nep­tune, the most dis­tant plan­et from the sun, is about 30 AU. NASA’s Voy­ager 1, humankind’s most dis­tant space­craft, is around 125 AU. It will take about 300 years for Voy­ager 1 to reach the inner edge of the Oort Cloud and pos­si­bly about 30,000 years to fly beyond it.
dif­fer­ent from the solar mag­net­ic field inside.

One of features of voyager is this golden disk, with a map of how to get to earth, pictures of mankind, and sounds of humanity. Sort of like throwing a note in a bottle out to sea- I wonder if anyone will ever read it, and if we’ll still be around.

Planet, or star?


It used to be simple. Star were the objects that shined. Planets go around stars. But the hunt for ever-colder star-like bodies two years ago led to a a new class of such objects. However, until now no one has known exactly how cool their surfaces really are – some evidence suggested they could be room temperature.

A new study shows that while these brown dwarfs, sometimes called failed stars, are indeed the coldest known free-floating celestial bodies, they are warmer than previously thought with temperatures about 250-350 degrees Fahrenheit. To reach such low surface temperatures after cooling for billions of years means that these objects can only have about 5 to 20 times the mass of Jupiter. Unlike the Sun, these objects’ only source of energy is from their gravitational contraction, which depends directly on their mass.

“If one of these objects was found orbiting a star, there is a good chance that it would be called a planet,” says Trent Dupuy, a Hubble Fellow at the Harvard-Smithsonian Center for Astrophysics. But because they probably formed on their own and not in a proto-planetary disk, astronomers still call these objects brown dwarfs even if they are “planetary mass.”

The new data also present new puzzles to astronomers that study cool, planet-like atmospheres.
Planets, stars, orin between? Additional objects discovered in the past two years remain to be studied and will hopefully shed light on some of these outstanding issues.