Source
Scholastic News Online

Scholastic News Online is a free resource with breaking news and highlights from the print magazine.

Available for grades 1-6, Scholastic News magazine brings high-interest current events and nonfiction to millions of classrooms each week.

Additionally, our subscribers have FREE access to Scholastic News Interactive, an exclusive online learning tool featuring digital editions, videos, interactive features, differentiated articles, and much more.


Artist's rendering of system Gliese 581 "Planet e" in the foreground of this artist's rendering is twice the mass of Earth and closest to its sun. "Planet d," the blue dot, is the fourth planet out and may be at the right distance to have liquid water, scientists say. (Illustration: ESO)

Another Earth?

Astronomers discover the smallest exoplanets yet, and they might be similar to our planet

By Dante A. Ciampaglia | May 8 , 2009

hen the National Aeronautics and Space Administration (NASA) launched its Kepler telescope in March, the space agency hoped to find the first Earthlike planets outside our solar system.

As NASA waits for Kepler to start sending back images and data, a group of European astronomers is stealing NASA's thunder.

On April 21, a team of Swiss and French researchers working at the European Southern Observatory in Chile reported they had discovered the smallest and most Earthlike planets ever seen beyond our solar system.

Astronomers found the planets in a solar system called Gliese 581. It's a system of four planets orbiting a dim red star called a red dwarf. Gliese 581 is about 20 light-years from Earth.

The team has been studying Gliese 581 for four years. In 2007, it discovered three planets in the systems. Researchers named the planets 581b, 581c, and 581d. At the time, scientists ruled out the possibility of any liquid water or life on any of the three planets.

But now the researchers have changed their minds about planet 581d. Their recent research tells them that 581d is in just the right orbit and position for liquid water to possibly be there. That would mean the planet could sustain life.

According to the researchers, planet 581d is about seven times as big as Earth, too big to be just rock. So they think there could be a liquid ocean on its surface. Stephane Udry, one of the researchers, says the planet is the first serious "water world candidate" observed outside our solar system.

Another discovery made by the astronomers is the Gliese 581 system's fourth planet, called 581e.

This planet is far too close to its sun to sustain life. Its orbit puts it so close to its sun that the planet would be super hot and bombarded with radiation.

But the planet's size has astronomers excited. Planet 581e is similar in size to Earth. According to scientists, it could be about 1.9 times the size of Earth.

Scientists usually discover planets that exist outside our solar system—called exoplanets—using what they call the wobble method. They will watch a star, and if there is a wobble in its light, that might mean that a planet's gravity is influencing the star's gravitational pull. More than 340 planets have been discovered that way since 1995. Most have been about the size of Jupiter.

But Earthlike planets are too small and have too weak a gravitational pull to be found using the wobble method. Instead, astronomers use disruptions in starlight to zero in on these planets. It's a much more difficult task.

But by discovering these small planets, scientists have taken the first steps toward finding an actual Earthlike planet in another solar system.

"I think it's an amazing discovery," said Jon Jenkins, a principal investigator on NASA's Kepler mission. "There should be many more planets similar to these. I think we're seeing just a glimpse of what's out there."

TELL US WHAT YOU THINK

Read today’s story and answer the following question.

blog it If you could create your own planet, what geographical features would you make a part of it? Would it sustain human life? Animals? Plants? Would there be oceans and mountains, or would you create something entirely new?

Tell us what you think on the Scholastic News Online Blog!

MORE NEWS FOR KIDS

Get the latest on national and international events, movies, television, music, sports, and more from Scholastic News Online.

 

  • Teacher Store
  • The Teacher Store  
    Space Stations

    Space Stations

    by Diane M. Sipiera

    True Books have been upgraded and updated. Information is presented in a thorough yet engaging manner, featuring lively sidebars, a glossary, visual back matter, and an index.

    $5.21 You save: 25%
    Paperback Book | Grade 3
    Add To Cart
    Educators Only
    Space Stations
    Grade 3 $5.21
    Add To Cart
  • Teacher Store
  • The Teacher Store  
    Ellen Ochoa

    Ellen Ochoa

    by Pamela Walker

    This emergent-reader series introduces an array of interesting topics—biographies, American symbols, and more—with carefully leveled text approved by distinguished reading experts.

    $3.71 You save: 25%
    Paperback Book | Grades K-2
    Add To Cart
    Educators Only
    Ellen Ochoa
    Grades K-2 $3.71
    Add To Cart
Privacy Policy
EMAIL THIS

* YOUR FIRST NAME ONLY

* FRIEND'S FIRST NAME ONLY

* FRIEND'S EMAIL ADDRESS

MESSAGE
Here's something interesting from Scholastic.com