Site Map

 and the 
Search for Extra-Solar Planets

[Whoa!  The search for planets by using transits has progressed so quickly that I can't keep up with all of the discoveries.  While that in itself is good news, this page quickly becomes dated. I will resume updating this page at a later date.  Thanks for understanding.]
SOHO spacecraft monitors the sun.

SOHO astronomers note...  

  • Venus can likely be used "for calibration purposes for both LASCO and UVCS coronagraphs. Its brightness can be used for refining visible light radiometric quantities and its position (before the transit) can be used for absolute pointing corrections.  During the transit on the disk, Venus may be similarly useful for the disk imagers (EIT and MDI)." --Leonard Strachan
  • "Unfortunately, the Venus transit will not be a disk transit seen from SOHO. Although we're roughly in the same direction as Earth seen from the Sun, there are some differences (the Sun is a very powerful radio source, so to avoid interference with our downlink we can never be directly in from of the Sun as seen from Earth).  It will be a coronal transit, though, much like the Mercury transit of 1999 (see  Venus will be a much bigger dark spot, though!"   --Stein Vidar Hagfors Haugan

SOHO's HGA Keyhole
The satellite's Keyhole--its definition, its significance, its challenges, its impact--is well explained as SOHO takes the pulse of the sun.  See what the SOHO team is thinking and how they respond to satellite challenges. 04-01-22

SOHO captures Mercury transit on May 7, 2003.  Still images and movies available.
NASA's newly approved Kepler mission will search for earth-class planets by looking for transits of planets around 100,000 distant stars.
"Solar Transits: Tools of Discovery" article by Edna DeVore describes how transits are significant both as historical events and as cutting-edge research tools.
California & Carnegie Planet Search keeps you current on exo-planet research and almanacs.

a series of transits

"Search for extra-solar planets, or planets orbiting stars other than the Sun, by the transits they make..."

Plot of planet
SETI document describes detecting other worlds using the  photometric transit or 'wink' method; by Dr. Laurance Doyle.

Press release (Jan. 6, 2003) announces first planet detected by transit method, which used ground-based telescopes.
ESO press release (April 22, 2003) announces discovery of glowing hot transiting exoplanet. 
Press release (August 24, 2004): "Network of small telescopes discovers distant planet (TrES-1)."  Image courtesy of NASA JPL.

Artist's concept of the Large Binocular Telescope 
Large Binocular Telescope (LBT) "will enable astronomers to carry out a broad range of unprecedented astronomical observations, including some of the first direct observations of giant planets around other stars."
TRACE spacecraft captures image of Mercury transiting sun in 1999.
TRACE spacecraft captures image of Mercury transiting sun in 2003.  For more transit of Mercury images and movies see

See Explanation.  Clicking on the picture will download 
 the highest resolution version available.
False color x-ray images of Mercury transiting sun taken by the Yohkoh satellite.
A collection of educational materials relating to the sun, its effects, and the Genesis mission.  The Genesis spacecraft, sent "a million miles sunward to collect pieces of the sun, called solar wind, ... unfolded its collectors and began a two-year 'sunbath.'  Upon its return to Earth in 2004, scientists will study the solar wind samples."
Animations show Messenger spacecraft imaging Venus during a flyby on June 24, 2004, after the transit of Venus.

The solar image in our logo is from the SOHO spacecraft.

Venus Transit banner
Sun-Earth Day resources from the fun folks at the Sun-Earth Connection Education Forum.
"The Canadian Space Agency satellite SCISAT-1 (ACE) is set to take Venus Transit measurements using its on-board high-resolution Fourier transform spectrometer.  SCISAT-1 will observe the transit as part of the ACE studies that are measuring and understanding the chemical processes that control the distribution of atmospheric ozone in the Arctic;" from the University of Waterloo.

Copyright 2003-2008 Chuck Bueter.  All rights reserved.