Featured Research

from universities, journals, and other organizations

Rosetta-Alice spectrograph obtains first far ultraviolet spectra of a cometary surface

Date:
September 4, 2014
Source:
Southwest Research Institute
Summary:
NASA's Alice ultraviolet spectrograph aboard the European Space Agency's Rosetta comet orbiter has delivered its first scientific discoveries. Rosetta, in orbit around comet 67P/Churyumov-Gerasimenko, is the first spacecraft to study a comet up close.

The Alice ultraviolet imaging spectrometer will be the first to study a comet up close. The shoebox-sized instrument is one-third to one-half the mass of comparable UV instruments, yet with more than 10,000 times as many imaging pixels as the spectrometer aboard Galileo.
Credit: Image courtesy of Southwest Research Institute

NASA's Alice ultraviolet (UV) spectrograph aboard the European Space Agency's Rosetta comet orbiter has delivered its first scientific discoveries. Rosetta, in orbit around comet 67P/Churyumov-Gerasimenko, is the first spacecraft to study a comet up close.

Related Articles


As Alice began mapping the comet's surface last month, it made the first far ultraviolet spectra of a cometary surface. From these data, the Alice team discovered that the comet is unusually dark at ultraviolet wavelengths and that the comet's surface -- so far -- shows no large water-ice patches. Alice is also already detecting both hydrogen and oxygen in the comet's coma, or atmosphere.

"We're a bit surprised at both just how very unreflective the comet's surface is, and what little evidence of exposed water-ice it shows," says Dr. Alan Stern, Alice principal investigator and an associate vice president of the Southwest Research Institute (SwRI) Space Science and Engineering Division.

Developed by SwRI, Alice is probing the origin, composition and workings of the comet, gaining sensitive, high-resolution compositional insights that cannot be obtained by either ground-based or Earth-orbital observations. The ultraviolet wavelengths Alice observes contain unique information about the composition of the comet's atmosphere and the properties of its surface.

"As the mission progresses, we will continue to search for surface ice patches and ultraviolet color and composition variations across the surface of the comet," says Dr. Lori Feaga, Alice co-investigator at the University of Maryland.

Alice is one of three instruments funded by NASA flying aboard Rosetta. Alice has more than 1,000 times the data-gathering capability of instruments flown a generation ago, yet it weighs less than 4 kilograms and draws just 4 watts of power. A sister Alice instrument was developed by SwRI and was launched aboard the New Horizons spacecraft to Pluto in January 2006 to study that distant world's atmosphere. It will reach Pluto in July 2015. SwRI also built and operates Rosetta's Ion and Electron Spectrograph (IES), another instrument with miniaturized electronic systems. With a mass of 1.04 kilograms, IES achieves sensitivity comparable to instruments weighing five times more.

To reach its comet target, the Rosetta spacecraft executed four gravity assists (three from Earth, one from Mars) and a nearly three-year period of deep space hibernation, waking up in January 2014 in time to prepare for its rendezvous with Churyumov-Gerasimenko. Rosetta also carries a lander, Philae, that will drop to the comet's surface in November 2014, attempting the first-ever direct observations of a comet surface.

Rosetta is an ESA mission with contributions from its member states and NASA. Rosetta's Philae lander is provided by a consortium led by DLR, MPS, CNES and ASI. Airbus Defense and Space built the Rosetta spacecraft. NASA's Jet Propulsion Laboratory (JPL) manages the U.S. contribution of the Rosetta mission for NASA's Science Mission Directorate in Washington, under a contract with the California Institute of Technology (Caltech). JPL also built the Microwave Instrument for the Rosetta Orbiter and hosts its principal investigator, Dr. Samuel Gulkis. SwRI (San Antonio and Boulder, Colo.) developed the Rosetta orbiter's Ion and Electron Sensor and Alice instrument and hosts their principal investigators, Dr. James Burch (IES) and Dr. Alan Stern (Alice).


Story Source:

The above story is based on materials provided by Southwest Research Institute. Note: Materials may be edited for content and length.


Cite This Page:

Southwest Research Institute. "Rosetta-Alice spectrograph obtains first far ultraviolet spectra of a cometary surface." ScienceDaily. ScienceDaily, 4 September 2014. <www.sciencedaily.com/releases/2014/09/140904153803.htm>.
Southwest Research Institute. (2014, September 4). Rosetta-Alice spectrograph obtains first far ultraviolet spectra of a cometary surface. ScienceDaily. Retrieved March 29, 2015 from www.sciencedaily.com/releases/2014/09/140904153803.htm
Southwest Research Institute. "Rosetta-Alice spectrograph obtains first far ultraviolet spectra of a cometary surface." ScienceDaily. www.sciencedaily.com/releases/2014/09/140904153803.htm (accessed March 29, 2015).

Share This


More From ScienceDaily



More Space & Time News

Sunday, March 29, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

What NASA Wants To Learn From Its 'Year In Space' Tests

What NASA Wants To Learn From Its 'Year In Space' Tests

Newsy (Mar. 28, 2015) Astronaut Scott Kelly and cosmonaut Mikhail Kornienko will spend a year in space running tests on human physiology and psychology. Video provided by Newsy
Powered by NewsLook.com
Crew Starts One-Year Space Mission

Crew Starts One-Year Space Mission

Reuters - News Video Online (Mar. 28, 2015) Russian-U.S. crew arrives safely at the International Space Station for the start of a ground-breaking year-long stay. Paul Chapman reports. Video provided by Reuters
Powered by NewsLook.com
Why So Many People Think NASA's Asteroid Mission Is A Waste

Why So Many People Think NASA's Asteroid Mission Is A Waste

Newsy (Mar. 27, 2015) The Asteroid Retrieval Mission announced this week bears little resemblance to its grand beginnings. Even NASA scientists are asking, "Why bother?" Video provided by Newsy
Powered by NewsLook.com
Space Station Crew Docks Safely

Space Station Crew Docks Safely

Reuters - News Video Online (Mar. 27, 2015) NASA TV footage shows the successful docking of a Russian Soyuz craft to the International Space Station for a year-long mission. Rough cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins