Download Video
Video Information
Subscribe to Series
How to Map a Very Faraway Planet
Scientists using NASA's Spitzer Space Telescope were able to create the first-ever map of the surface of a planet beyond our solar system. The planet, a hot and cloudy gas giant called HD 189733b, is located 60 light-years from Earth in the constellation Vulpecula. It is so far away that even the best telescopes can't distinguish the light of the planet from that of its star. So how did astronomers see this planet's cloudy surface?
They used Spitzer's infrared vision to observe the HD 189733 system as the planet, HD 189733b, first crossed in front of its parent star, then passed behind, as illustrated in this movie. HD 189733b is what is known as a transiting planet, which means that it is inclined in such a way that it eclipses its star from Earth's point of view. This planet is also thought to be tidally locked to its star, meaning that one face, termed the day side, always "looks at" its fiery hot sun.
Spitzer began observing the planet when it was between us and the star, with its cooler, dimmer night side in view. As the planet swept around, the hotter and brighter day side rotated into view, and the total infrared light measured by Spitzer went up. The size of this increase in infrared brightness over time told astronomers how the temperature across the entire surface of the planet varies.
Why did the scientists use infrared light? This astronomical trick works best with infrared light, because a planet's own light stands out more in comparison to its glaring sun at this wavelength. For example, if this star/planet system were viewed in visible light, the light from the planet itself would be washed out. Since infrared light tells astronomers how much heat is coming from a planet, it can also be used to determine temperatures.
The map reveals that HD 189733b is about 1,200 degrees Fahrenheit (650 degrees Celsius) on its dark side, and about 1,700 degrees Fahrenheit (930 degrees Celsius) on its sunlit side. Such a mild temperature variation indicates that strong winds are sweeping hot gas from the sunlit side over to the dark side.
Related Media
 |
News Release NASA Finds Extremely Hot Planet, Makes First Exoplanet Weather Map ssc2007-09 |
 |
Image First Map of an Alien World ssc2007-09a |
|
Image Blacker than Black ssc2007-09b |
 |
Video Blacker than Black ssc2007-09v1 |
|
Video Mapping Exotic Worlds ssc2007-09v2 |
 |
Video How to Map a Very Faraway Planet ssc2007-09v3 |
|
Video The X-Planets (Showcase) hiddenuniverse016 |
Most Popular Videos
Spitzer Podcasts
Browse Videos in Science Animations
11.29.07 Pulling Back the Curtain of DustThis artist's animation begins by showing a dark and dusty corner of space where little visible light can escape. The... |
05.09.07 Blacker than BlackThis artist's animation illustrates the hottest planet yet observed in the universe. The scorching ball of gas, a "ho... |
05.09.07 Mapping Exotic WorldsThis animation shows the first-ever map of the surface of an exoplanet, or a planet beyond our solar system. The map,... |
05.09.07 How to Map a Very Faraway PlanetScientists using NASA's Spitzer Space Telescope were able to create the first-ever map of the surface of a planet bey... |
04.18.07 Infrared RoseThis movie begins by showing an optical image of the Rosette nebula, a turbulent star-forming region located 5,000 li... |
04.18.07 Highway to the Danger Zone"The further on the edge, the hotter the intensity," sings Kenny Loggins in "Danger Zone," a song made famous by the ... |
03.29.07 Two Suns Raise Family of Planetary BodiesThis artist's animation depicts a faraway solar system like our own -- except for one big difference. Planets and ast... |
02.21.07 Hot, Dry, and Cloudy (Artist Concept)This artist's concept animation shows a cloudy Jupiter-like planet that orbits very close to its fiery hot star. NASA... |
12.18.06 Stars Spring Up Out of the DarknessThis artist's animation illustrates the universe's early years, from its explosive formation to its dark ages to its ... |
11.07.06 Hubble-Spitzer OrionThis video cycles between the Hubble view, the Spitzer view, and the combined Hubble-Spitzer view of the Orion Nebula. |
11.07.06 Making a Great Observatories CompositeThis video shows how a Hubble image and a Spitzer image of the Orion Nebula were combined to create a new, multi-wave... |
10.30.06 Who Ya Gonna Call?NASA's Spitzer Space Telescope is a galactic ghost buster, spotting hidden massive stars and other monsters lurking i... |
10.26.06 Order Amidst Chaos of Star's ExplosionThis artist's animation shows the explosion of a massive star, the remains of which are named Cassiopeia A. NASA's Sp... |
10.12.06 Fire and Ice PlanetThis artist's animation shows a blistering world revolving around its nearby "sun." NASA's infrared Spitzer Space Tel... |
10.12.06 Fire and Ice Planet (without data plot)This artist's animation shows a blistering world revolving around its nearby "sun." NASA's infrared Spitzer Space Tel... |
08.14.06 Journey to OrionThis movie begins with a visible view of the famous Orion constellation. Superimposed on the area near Orion's sword ... |
07.24.06 Stars Can't Spin Out of ControlThis artist's animation demonstrates how a dusty planet-forming disk can slow down a whirling young star, essentially... |
06.05.06 Fade to RedThis animation shows the Andromeda galaxy, first as seen in visible light by the National Optical Astronomy Observato... |
04.05.06 Birth of 'Phoenix' Planets?This artist's animation depicts the explosive death of a massive star, followed by the creation of a disk made up of ... |
03.16.06 Cigar Galaxy up in SmokeThis movie compares a visible-light view of the "Cigar galaxy" to an infrared view from NASA's Spitzer Space Telescop... |
