Thanks to new telescopic imaging techniques, astronomers no longer have to speculate about the existence of planets outside our solar system. Now they—and we—can actually see them.

Over the past several years, astronomers have discovered hundreds of planets outside our solar system with what they call the “wobble technique,” in which small color changes of a star allow scientists to indirectly infer the presence of planets in orbit around it.
Now two teams of researchers—one at University of California, Berkeley, the other at the Herzberg Institute of Astrophysics in Victoria, British Columbia—have achieved the first direct views of extrasolar planets.
Working with photographs taken by the Hubble Space Telescope, the Berkeley researchers, headed by Dr. Paul Kalas, have identified a planet orbiting the star Fomalhaut, which lies 25 light-years from Earth in the constellation Piscis Austrinus.
Meanwhile, Dr. Christian Marois and his team at the Herzberg Institute have taken the first successful photograph of extrasolar planets from Earth’s surface. Using the Keck and Gemini telescopes on the Big Island of Hawaii, they captured images of three gaseous planets around a star 130 light-years away known as HR 8799.
“This is an important discovery for science and for the field of astronomy,” Marois says. “We have been looking for other planets for so many years—to actually see them is incredible.”
The new photographic technique, which allows astronomers to take direct images of the planets, also enables them to estimate some of their physical characteristics, such as temperature and molecular composition.

In FLYP’s sideshow, check out the latest photographs of distant planets orbiting other stars, and listen to descriptions of the significance of each image.

Marois hopes that this development will help to clear up a fundamental question about planet formation: are they created by gravitational instability (a situation in which an object’s self-gravity exceeds opposing forces such as internal gas pressure or material rigidity, and the object collapses) or by core accretion (wherein small particles accumulate to build up planetary cores)?
None of the planets photographed so far is likely to harbor any form of life. The HR 8799 solar system, one of many Marois’s team is studying, is only 60 million years old (our own is 4.6 billion years old), and the thermal energy from its creation is believed to be still too high to sustain any forms of life.
These planets may, however, serve to protect life elsewhere, since their great mass attracts asteroids and other objects in space that could otherwise destroy more temperate planets.
“Our discovery shows that there is a lot of diversity out there,” Marois says. “In the next few years, there will be many more findings.”