Mercury's 'tail' is longer than thought

February 27, 2008

U.S. scientists have used sodium atoms to determine Mercury's comet-like tail is much longer than had been thought.

Mercury's gravity is too weak to hold a permanent atmosphere, so when atoms are evaporated from the planet's surface by solar photons or other processes, some of the atoms form a tail that points away from the sun.

Jeffrey Baumgardner and colleagues at Boston University's Center for Space Physics studied the bright yellow-orange light emitted by the sodium atoms in Mercury's tail and discovered the tail, previously detected to 15 times the radius of Mercury, actually extends more than 100 times that distance, or 1.6 million miles from the planet.

The physicists also discovered the time it takes for the sodium atoms to leave Mercury's surface and reach the tail's maximum length is approximately 15 hours.

The research by Baumgarder, Jody Wilson and Michael Mendillo appears in the journal Geophysical Research Letters.

Copyright 2008 by United Press International

Explore further: Hubble sees a celestial swan and butterfly

Related Stories

Hubble sees a celestial swan and butterfly

June 5, 2012

(Phys.org) -- This image from the Hubble Space Telescope shows planetary nebula NGC 7026. Located just beyond the tip of the tail of the constellation of Cygnus (The Swan), this butterfly-shaped cloud of glowing gas and dust ...

MESSENGER results after six months in orbit

October 5, 2011

(PhysOrg.com) -- MESSENGER scientists will highlight the latest results on Mercury from MESSENGER observations obtained during the first six months (the first Mercury solar day) in orbit. These findings will be presented ...

Extreme effects: Seven things you didn't know about Mercury

September 1, 2010

Pity poor Mercury. The tiny planet endures endless assaults by intense sunlight, powerful solar wind and high-speed miniature meteoroids called micrometeoroids. The planet's flimsy covering, the exosphere, nearly blends in ...

Recommended for you

New study sheds light on end of Snowball Earth period

August 24, 2015

The second ice age during the Cryogenian period was not followed by the sudden and chaotic melting-back of the ice as previously thought, but ended with regular advances and retreats of the ice, according to research published ...

Earth's mineralogy unique in the cosmos

August 26, 2015

New research from a team led by Carnegie's Robert Hazen predicts that Earth has more than 1,500 undiscovered minerals and that the exact mineral diversity of our planet is unique and could not be duplicated anywhere in the ...

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

zevkirsh
not rated yet Feb 27, 2008
i wonder if those atoms aggregate in any concentrated area or ring....or if they just keep moving into space in a dispersed manner. perhaps we could send a sattelite the ring to check it out.
seanpu
not rated yet Feb 28, 2008
there is no "dispersed manner" about the tail. if the atoms where just atoms they'd fly off every which way. in fact the atoms are actually highly charged ions and as such form a plasma-tail. the "end" of the tail will fall into the plasma system within our solar system. this hasn't yet been mapped.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.