TRAPPIST-1: A Star with 7 Earths?
On Feb. 22, 2017, scientists announced the discovery of TRAPPIST-1, an alien solar system with at least seven Earth-sized planets. See pictures of the discovery here. Read the Full Story.
Artist's impression of the cool dwarf star TRAPPIST-1 and its exoplanets, which lie 39 light-years from Earth.
The seven planets in the TRAPPIST-1 system range in mass from 75 percent to 110 percent that of Earth. At least three of the worlds likely have surface temperatures that allow liquid water to exist, scientists say.
TRAPPIST-1 Orbit Diagram
Diagram of the orbits of the TRAPPIST-1 worlds, compared to those of Jupiter's Galilean moons, Mercury, Venus and Earth.
View from the Surface of a TRAPPIST-1 Planet
Artist's impression of the view from the surface from one of the seven Earth-size planets in the TRAPPIST-1 system.
TRAPPIST-1 Planets and the Solar System's Rocky Worlds
Characteristics of the seven TRAPPIST-1 worlds, compared to the rocky planets in our solar system.
2016 Discovery: 3 TRAPPIST-1 Planets
In 2016, astronomers announced the discovery of three Earth-size worlds in the TRAPPIST-1 system. Additional observation upped eventually upped that tally to seven.
TRAPPIST-1 Planet: Surface View
Another artist's impression of the view from a TRAPPIST-1 planet's surface.
TRAPPIST-1 Planetary System: Artist's Concept
Artist's illustration of two Earth-size exoplanets crossing the face of the dim star TRAPPIST-1, which lies just 39 light-years from Earth.
TRAPPIST-1 System: Size Comparison
Diagram showing the sizes of the TRAPPIST-1 star and planets, compared to objects in our own solar system. The star TRAPPIST-1 is only slightly bigger than Jupiter.
Energy Fluxes in TRAPPIST-1 System
Diagram showing how much stellar energy the TRAPPIST-1 planets receive, compared to worlds in our own solar system.
TRAPPIST-1 System from Above
The orbits of the seven TRAPPIST-1 planets. The relative sizes of the planets are correct, but on a different scale to their distance to the star.
Planet Orbits Around TRAPPIST-1
This diagram shows the orbits of seven planets around the cool red dwarf star, TRAPPIST-1. The shaded area shows the star's "habitable zone," where a planet could have the right surface temperature for liquid water. The dotted lines show alternative boundaries to the habitable zone based on different "theoretical assumptions," according to a statement from the European Southern Observatory.
Planetary Transit of TRAPPIST-1
This chart shows how the red dwarf star TRAPPIST-1 appears to grow slightly dimmer each time one of its seven known planets crosses in front of the star )as seen from Earth).
This graph shows the star TRAPPIST-1 during a rare triple transit event. A planetary transit occurs when a planet passes between its parent star and the Earth, causing an apparent change in the star's brightness. In this case, three planets transited the star.
TRAPPIST-1 Brightness Profile
This diagram shows the brightness of the cool red dwarf star TRAPPIST-1 over 20 days. Dips in the brightness are caused by one or more planets orbiting in front of the star and briefly blocking its light.
TRAPPIST-1 Star v Sun
This artist's impression shows the size of Earth's sun compared to the cool red dwarf star TRAPPIST-1. Planets that orbit closer to the star than Mercury orbits the sun can still have surface temperatures cool enough to support liquid water.
TRAPPIST-1 Solar System Comparison
This diagram compares the TRAPPIST-1 planet system with Earth's solar system. The size of Earth's sun is shown with regard to the red dwarf star, TRAPPIST-1. The position of the seven planets around TRAPPIST-1 are shown in relation to Mercury's orbit around the sun.
TRAPPIST-1 Size Comparison
A size comparison of the TRAPPIST-1 system with the sun and the inner-most planets, as well as Jupiter and its largest moons.
TRAPPIST-1 and Galilean Moons
This diagram compares the TRAPPIST-1 system to the orbits of some of Jupiter's largest moons.
A Distant View in TRAPPIST-1
An artist's impression of what an observer might see standing on one of the more distant planets known to orbit the cool dwarf star TRAPPIST-1.
A View from TRAPPIST-1
An artist's impression of what it might look like from the surface of a planet in the TRAPPIST-1 system.
- Tariq Malik, Space.com Managing Editor
Tariq joined Purch's Space.com team in 2001 as a staff writer, and later editor, covering human spaceflight, exploration and space science. He became Space.com's Managing Editor in 2009. Before joining Space.com, Tariq was a staff reporter for The Los Angeles Times. He is also an Eagle Scout (yes, he has the Space Exploration merit badge) and went to Space Camp four times as a kid and a fifth time as an adult. He has journalism degrees from the University of Southern California and New York University. To see his latest project, you can follow Tariq on Google+, Twitter and on Facebook.
- Tariq Malik, Space.com Managing Editor on