Download Video
Video Information
Subscribe to Series
Blacker than Black
This artist's animation illustrates the hottest planet yet observed in the universe. The scorching ball of gas, a "hot Jupiter" called HD 149026b, is a sweltering 3,700 degrees Fahrenheit (2,040 degrees Celsius) -- about three times hotter than the rocky surface of Venus, the hottest planet in our solar system. The planet is so hot that astronomers believe it is absorbing almost all of the heat from its star, and reflecting very little to no light. Objects that reflect no sunlight are black. Consequently, HD 149026b might be the blackest known planet in the universe, in addition to the hottest.
The temperature of this dark and balmy planet was taken with NASA's Spitzer Space Telescope. While the planet reflects no visible light, its heat causes it to radiate a little visible and a lot of infrared light. Spitzer, an infrared observatory, was able to measure this infrared light through a technique called secondary eclipse. HD 149026b is what is known as a transiting planet, which means that it crosses in front of and passes behind its star -- the secondary eclipse -- when viewed from Earth. By determining the drop in total infrared light that occurs when the planet disappears, astronomers can figure out how much infrared light is coming from the planet alone.
The Spitzer observations of HD 149026b also suggest a hot spot in the middle of the side of the planet that always faces its star. Even though the planet is black, the spot would glow like a black lump of charcoal. HD 149026b is thought to be tidally locked, just as our moon is to Earth, such that one side of the planet is perpetually baked under the heat of its sun.
Astronomers think that HD 149026b is probably blazing hot on its sunlit side, and much cooler on its dark side. A similar phenomenon was observed previously by Spitzer for the planet Upsilon Andromedae b. In the case of both planets, heat is not being evenly distributed across their surfaces. This is the opposite of what happens on Jupiter, where temperature differences are minimal all around.
HD 149026b is located 256 light-years away in the constellation Hercules. It is the smallest known transiting planet, with a size similar to Saturn's and a suspected dense core 70 to 90 times the mass of Earth. It speeds around its star every 2.9 days.
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
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 Planet (without data plot)This artist's animation shows a blistering world revolving around its nearby "sun." NASA's infrared Spitzer Space Tel... |
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... |
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... |
06.09.05 The Cry of Cassiopeia AThis animation begins with a stunning false-color picture of the supernova remnant Cassiopeia A. It is made up of ima... |
06.02.05 Space Eyes See Comet Tempel 1This artist's concept of Tempel 1 illustrates the comet's shape, reflectivity, rotation rate and surface temperature,... |
05.30.05 Pillars Behind the DustThe movie begins with a visible-light picture of the southern region of our Milky Way galaxy then slowly zooms into t... |
05.30.05 Carina in ContextThis animation starts with an image of a larger but lower resolution image of the Carina Nebula from the Midcourse Sp... |
05.04.05 A More Spectacular SombreroThis movie shifts from the well-known visible-light picture of Messier 104 taken by the Hubble Space Telescope to inf... |
04.20.05 Band of RubbleThis artist's animation illustrates a massive asteroid belt in orbit around a star the same age and size as our Sun. ... |
