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Asteroids with rings around them. A new accurate measurement to the center of our galaxy. The
largest 360 degree panorama of our Milky Way galaxy is released.
Hello Space Fans! Welcome to another edition of Space Fan News!
When we imagine asteroids, the image that pops into our mind is almost always a piece
of space rock slowly floating in space, with the majority of them between Mars and Jupiter
in what we call the asteroid belt.
With that in mind, imagine the surprise of astronomers to observe a large “Centaur”
asteroid with…. Rings around it!
The object is named Chariklo and astronomers were caught off guard to see these rings as
the frozen minor planet crossed the path of light of a star behind it.
This method of detecting things should seem familiar, as it’s what Kepler used to detect
exoplanets. Astronomers have been waiting since June of 2013 for the time when Chariklo
would occult the far off star, and it was definitely worth it. When going over the data,
astronomers noticed distinct dips in light measurements a few seconds before and a few
seconds after Chariklo passed in front of the star. And since this observation was being
done by not just one, but seven telescopes from across the world, the data was easily
confirmed.
Chariklo was first discovered in 1997 by James V. Scotti and its orbit is between Saturn
and Uranus. It gets its centaur designation because it acts like both an asteroid and
a comet, thusly named after the mythological creature of half human, half horse.
Scientists still aren’t exactly sure how these rings formed, but think it’s likely
the result of a collision that happened a long time ago, allowing for the ejected debris
that didn’t attain escape velocity to find a relatively stable orbit around Chariklo.
Up until this time, there was no reason to even consider that objects this small would
have ring systems around it, but here you are: two distinct thin rings wrapping around
it. I guess Beyonce was right, if you like it, you better put a ring on it. Whatever
was hitting on Chariklo did exactly that.
Radio astronomers from three international teams have given us the most precise measurement
from our solar system to the center of our galaxy: 27,190 light-years. NRAO’s Very
Long Baseline Array, the European Very-long-baseline interferometry array and the Japanese VERA
project all worked together to find this accurate distance which is said to be within a 2% margin
of error.
Or as Mark Reid from the Harvard-Smithsonian Center for Astrophysics said, “more accurate
than most road-sign mileages.”
So what’s the big deal? What does knowing how close we are to the galactic center actually
DO for us?
Well just like most units of measurement that we use in our daily lives, they’re based
off of other measurable things. A liter is the volume of 1000 cubic centimeters. A light-year
is the distance that light travels in a vacuum in one Julian year. We’re able to use these
units of measure by precisely measuring the components that make it up. A light-year would
mean nothing to us if we couldn’t accurately measure the velocity of light in a vacuum.
Same goes with knowing our distance to the center of the galaxy. It allows us to better
understand the motion and mass of other objects throughout the galaxy, as well as their luminosity.
Studying this light with a better understanding of how far away they are and what is affecting
them gives us further insight into our stellar neighborhood.
Since we’re INSIDE the galaxy, it makes it very difficult to do things like map it.
Kind of like not seeing the forest because of all the trees. These precise techniques
have even produced results more accurate than GAIA will be able to produce. The silver lining
on that is that GAIA isn’t looking only in towards the galactic center, but all around
us, mapping 1 billion stars. The data from Gaia will be complimented with this technique
from radio astronomers to better know our Milky Way.
Finally, speaking of our Milky Way, one of the most beautiful panoramas of our galaxy
that I’ve ever seen was released at the TED conference in Vancouver. It’s a completely
interactive 360-degree view of our galaxy in the infrared wavelength thanks to data
from the Spitzer Space Telescope.
The team from Wisconsin took over 10 years of Spitzer data and stitched together the
images to create this awe-inspiring image. The GLIMPSE360 picture was compiled by Barb
Whitney from the University of Wisconsin, Madison. Want to know the best part? You can
get in and play with the imagery yourself.
It’s been released as part of Microsoft Research’s World Wide Telescope program.
If you’re on a Windows machine, I recommend installing the WWT program to get the full
effect, but you can still use World Wide Telescope within an Internet Browser.
Make sure to click the links below in the description to get access to this free tool.
You won’t regret it.
Well that’s it for this week Space Fans. Tony and I look forward to hanging out with
you tonight at 9p.m. Eastern, 6 p.m. Pacific time for Space Fan News Live! Make sure to
bring your questions and comments so we can respond to them on air! Follow us over on
Twitter and don’t forget to subscribe!
Thank you ALL for watching and… as always… keep looking up!