Taxonomy term


TRAPPIST-1 system hosts seven "Earth-like" planets

In 2017, astronomers discovered seven planets orbiting a star dubbed TRAP­PIST-1, a faint red dwarf 40 light-years from Earth and only 9 percent as bright as our sun. The Earth-like qualities of these planets made headlines: they are of similar sizes to our planet, and their orbits fall within TRAPPIST-1’s habitable zone — two characteristics that scientists think are important for life to exist on a planet. Researchers now report that the TRAPPIST-1 planets have even more traits in common with Earth: they are likely rocky, and they may have surface water that exists as liquid, ice and vapor.

08 Jun 2018

Second stars can distort planet size estimates

When light from a star is blocked by another celestial body — as when the moon obstructed light from the much-larger sun during the recent solar eclipse — astronomers can estimate the density of exoplanets that orbit the star. And from the density, they can determine whether a planet is rocky like Earth or gaseous like Jupiter. But a new study in the Astronomical Journal shows that such density assessments, which are normally calculated from the size of the planet, may be skewed by the presence of “hidden” stars.

08 Nov 2017

Newly discovered Earth-like worlds are rocky, not gassy

In May, a new planetary system was discovered just 40 light-years from Earth, including three Earth-sized planets orbiting around their red dwarf sun in a temperature range that could potentially harbor life. Now, a follow-up study on the system has found that the two innermost planets are primarily rocky with compact atmospheres, as opposed to inhospitable gas giants, like Jupiter.

15 Nov 2016

Conjunction injunction: Recent and future planetary alignments

February 1962: The five planets visible to the naked eye, as well as the sun and moon, all appeared within 17 degrees of each other in the sky. A concurrent solar eclipse and new moon made it possible to view the planets.

04 Feb 2015

Benchmarks: February 4, 1962: Five planets align - but no end of the world

In the movie "2012," released in theaters last November, an alignment of five planets in our solar system — supposedly foretold by the Mayans thousands of years ago — causes horrors that span nearly every earth science disaster movie cliché: solar flares, neutrinos, earthquakes, volcanoes, floods, poles shifting, oceans washing over the tallest mountains in the world, cities falling into the sea, mass hysteria and, basically, total destruction of life as we know it.
04 Feb 2010

Super-Earths: Mirrors of our world?

Fifty light-years from Earth, in the constellation Pegasus, burns a yellow star not unlike our sun. The star, called 51 Pegasi, was one of 142 stars under the watchful gaze of Swiss astronomers Michel Mayor and Didier Queloz of the University of Geneva in 1994. From the La Silla Observatory at the southern end of Chile’s vast Atacama Desert, Mayor and Queloz were tracking how these stars move in the sky, hoping to determine whether the stars were alone — or whether any of them might be accompanied by a planet or two.

31 Jul 2009