Tau1 Gruis, the star that the newly discovered exoplanet orbits around.
Courtesy of NASA/JPL

More than 100 planets orbit distant stars!
News story originally written on September 25, 2002

Astronomers have identified another exoplanet, that is, a planet outside our solar system. This makes a total of 102 exoplanets that have so far been found by astronomers!

The astronomers that identified this exoplanet, have been searching outside our solar system for planets that are similar to Earth. They have been using the Anglo-Australian Telescope in New South Wales, Australia to search the southern skies. The planet they found is circling the star Tau1 Gruis and is three times as far from its star as Earth is from the Sun. The newly discovered planet has a mass similar to Jupiter’s and is about 100 light years away.

The solar system of this newly discovered planet is organized a bit like ours. The planets are strung out in a line from the star, with the larger ones furthest away. Now that researchers have found so many exoplanets, they can see patterns that suggest that solar systems like ours, with the high-mass planets orbiting much further out are more common than those whose high mass planets are clustered close to the star.

How do astronomers find exoplanets? They look for stars that appear to wobble because of the gravitational pull of orbiting planets. The wobble can be detected by a Doppler shift in the star’s light indicating the presence of a planet. This is then fine tuned to assess the planet’s distance from the star and mass.

After astronomers have a good idea which of the exoplanets are like Earth, their next step is to look for evidence of life by analyzing the chemistry of the planet and its atmosphere for molecules of carbon, carbon dioxide, and ozone. Perhaps they will someday find evidence that we are not alone in the universe!


You might also be interested in:

Cool It! Game

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

An Exoplanet that Looks Like Jupiter!

Astronomers Dr. Geoffrey Marcy and Dr. Paul Butler announced that, after 15 years of observation, their team has found 13 extrasolar planets (or exoplanets), and that one of these exoplanets may be somewhat...more

What is mass?

Would it be more difficult to pull an elephant or a mouse? If you pulled each animal with the same amount of force, the elephant would respond less to pulling, even if he didn’t pull back at all. That’s...more

1999--A Year in Review...

It was another exciting and frustrating year for the space science program. It seemed that every step forward led to one backwards. Either way, NASA led the way to a great century of discovery. Unfortunately,...more

STS-95 Launch: "Let the wings of Discovery lift us on to the future."

The Space Shuttle Discovery lifted off from Kennedy Space Center at 2:19 p.m. EST, October 29th. The sky was clear and the weather was great as Discovery took 8 1/2 minutes to reach orbit for the Unitied...more

Moon Found Orbiting Asteroid

A moon was discovered orbiting the asteroid, Eugenia. This is only the second time in history that a satellite has been seen circling an asteroid. A special mirror allowed scientists to find the moon...more

U.S. is Fed Up with Russia

Will Russia ever put the service module for the International Space Station in space? NASA officials are demanding an answer from the Russian government. The necessary service module is currently waiting...more

More on Recent Coronal Mass Ejection

During a period of about two days in early May, 1998, the ACE spacecraft was immersed in plasma associated with a coronal mass ejection (CME). The SWICS instrument on ACE, which determines unambiguously...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA