Super Venus in our cosmic neighborhood

Wolf 437, also called Gliese 486, is a red dwarf fairly close to the Sun – just 26 light-years away. What makes it interesting is a planet that astronomers now present in Science. Gliese 486 b moves around its parent star in a circular orbit within 1.5 days and at a distance of only 2.5 million kilometers (Earth: 150 million kilometers). Since its rotation around its own axis always takes the same time, the planet always turns the same side to its sun – similar to the moon to the earth.

Although the star Gliese 486 is much fainter and cooler than the Sun, its proximity to the planet heats its surface to at least 430 degrees Celsius. As a result, the surface of Gliese 486 b likely resembles that of Venus, with a hot and arid landscape covered with glowing lava flows. Calculations also show that the exoplanet has a composition similar to Venus and Earth, including a metallic core. Those who spend time on Gliese 486 b also feel an attractive force that is about 70 percent stronger than that on our home planet.

Unlike Venus, however, Gliese 486 b may have only a thin atmosphere – or none at all. Model calculations provide both scenarios, since planetary gas envelopes can evaporate over time under stellar irradiation. On the other hand, the planet’s gravity helps maintain them. It is difficult to determine the balance between these two factors mentioned above.

“The discovery of Gliese 486 b was a stroke of luck. Another 100 degrees hotter, and the entire surface of the planet would be lava. Its atmosphere would be vaporized rock,” says José A. Caballero of the Centro de Astrobiología (CSIC-INTA, Spain) and co-author of the study. “On the other hand, if Gliese 486 b were a hundred degrees colder, it would be unsuitable for further observations.”

Because of its close proximity, astronomers now hope to be able to view it more closely with future telescopes.

Artist’s impression of the surface of the newly discovered Gliese 486 b. With a temperature of about 430 °C (800 °F), the astronomers expect a Venus-like hot and dry landscape interspersed with glowing lava rivers. Gliese 486 b possibly has a tenuous atmosphere. (Image: RenderArea)

2 Comments

  • Wouldn’t one side be hot and the other cold?

    • Only if it has no atmosphere, otherwise there is a temperature gradient and very strong winds carrying the heat to the “back”.

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BrandonQMorris
  • BrandonQMorris
  • Brandon Q. Morris is a physicist and space specialist. He has long been concerned with space issues, both professionally and privately and while he wanted to become an astronaut, he had to stay on Earth for a variety of reasons. He is particularly fascinated by the “what if” and through his books he aims to share compelling hard science fiction stories that could actually happen, and someday may happen. Morris is the author of several best-selling science fiction novels, including The Enceladus Series.

    Brandon is a proud member of the Science Fiction and Fantasy Writers of America and of the Mars Society.