How to Make a Helium Atmosphere

Spitzer_sig15-009_500

spitzer_sig15-009 June 11th, 2015

Credit: NASA/JPL-Caltech

This diagram illustrates how hypothetical helium atmospheres might form. These would be on planets about the mass of Neptune, or smaller, which orbit tightly to their stars, whipping around in just days. They are thought to have cores of water or rock, surrounded by thick atmospheres of gas. Radiation from their nearby stars would boil off hydrogen and helium, but because hydrogen is lighter, more hydrogen would escape. It's also possible that planetary bodies, such as asteroids, could impact the planet, sending hydrogen out into space. Over time, the atmospheres would become enriched in helium.

With less hydrogen in the planets' atmospheres, the concentration of methane and water would go down. Both water and methane consist in part of hydrogen. Eventually, billions of years later (a "Gyr" equals one billion years), the abundances of the water and methane would be greatly reduced. Since hydrogen would not be abundant, the carbon would be forced to pair with oxygen, forming carbon monoxide.

NASA's Spitzer Space Telescope observed a proposed helium planet, GJ 436b, with these traits: it lacks methane, and appears to contain carbon monoxide. Future observations are needed to detect helium itself in the atmospheres of these planets, and confirm this theory.

Image Source: http://www.spitzer.caltech.edu/images/6065-sig15-009-How-to-Make-a-Helium-Atmosphere

Curator: Spitzer Space Telescope, Pasadena, CA, USA

Spitzer_sig15-009_1280
×
ID
sig15-009
Subject Category
Subject Name
Credits
NASA/JPL-Caltech
Type
Chart
Image Quality
Good
Distance Notes
Facility
Instrument
Color Assignment
Band
Bandpass
Central Wavelength
Start Time
Integration Time
Dataset ID
Notes
Coordinate Frame
Equinox
Reference Value
Reference Dimension
Reference Pixel
Scale
Rotation
Coordinate System Projection:
Quality
FITS Header
Notes
Creator (Curator)
Spitzer Space Telescope
URL
http://www.spitzer.caltech.edu
Name
Email
Telephone
Address
1200 E. California Blvd.
City
Pasadena
State/Province
CA
Postal Code
91125
Country
USA
Rights
Publisher
Spitzer Science Center
Publisher ID
spitzer
Resource ID
sig15-009.tif
Metadata Date
2015-06-11
Metadata Version
1.2
×

Detailed color mapping information coming soon...

 

×

There is no distance meta data in this image.