Mercury's 'tail' is longer than thought

Feb 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: Huge waves measured for first time in Arctic Ocean

add to favorites email to friend print save as pdf

Related Stories

Hubble sees a celestial swan and butterfly

Jun 05, 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 ...

MESSENGER results after six months in orbit

Oct 05, 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 ...

Recommended for you

Huge waves measured for first time in Arctic Ocean

14 hours ago

As the climate warms and sea ice retreats, the North is changing. An ice-covered expanse now has a season of increasingly open water which is predicted to extend across the whole Arctic Ocean before the middle ...

New research reveals Pele is powerful, even in the sky

20 hours ago

One might assume that a tropical storm moving through volcanic smog (vog) would sweep up the tainted air and march on, unchanged. However, a recent study from atmospheric scientists at the University of Hawai'i ...

Image: Wildfires continue near Yellowknife, Canada

20 hours ago

The wildfires that have been plaguing the Northern Territories in Canada and have sent smoke drifting down to the Great Lakes in the U.S. continue on. NASA's Aqua satellite collected this natural-color image ...

User comments : 2

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.