Friday, 1 July 2011

Ask an Expert: Join NASA in Measuring an Asteroid

Asteroid 253 Mathilde, a C type asteroid with a composition similar to 52 Europa

On the evening of July 3 at 11:05:30 p.m. EDT -- at a distance of 280 millon miles into space that poses no threat to Earth -- a wide path of viewing opportunity will pass in front of star TYC 0292-00339-1 in the constellation Virgo. The asteroid will eclipse the star's light for 17.9 seconds in a process known asoccultation. Here on Earth, astronomers can measure the exact length of time the star's light is blocked and use those calculations to help verify the size of 52 Europa -- and you can help with the observation!

View all details about this event.

Artist concept of a narrow asteroid belt

Dr. Bill Cooke and his team from NASA's Meteor Environment Office at the Marshall Space Flight Center will be watching the sky on the evening of July 3, 2011. Join them from 9:30 p.m. to midnight EDT for a live Web chat to ask your questions and observe the occultation via a live Ustream feed. Amateur astronomers who are observing the event can also report their observations via the associated Twitter feed.

A Saturn moon, Rhea, emerges after being occulted by the larger moon Titan.

For observers, a wide path of viewing opportunity is available from Florida through Montana and into Canada. The viewing path will be those areas of the country that fall between the two dark, diagonal lines on the map. The combined light of the asteroid and the star will drop by 2.1 mag to 12.1 mag -- the magnitude of the asteroid -- for at most 17.9 seconds.

So make plans to join NASA in measuring this asteroid's size. See you in chat!

How to Join the Chat

Joining the chat is easy. Simply return to this chat page a few minutes before 9:30 p.m. on Sunday, July 3. The chat module will appear at the bottom of this page. After you log in, wait for the chat module to be activated, then ask your questions!

More About the Chat Experts

Bill Cooke
Danielle Moser
Rhiannon Blaauw

The chat window will appear here approximately
thirty minutes before the start of the chat.

This chat requires Java to function. Please check your version by clicking here.

Janet Anderson, 256-544-0034
Marshall Space Flight Center, Huntsville, Ala.