NASA's Hubble Space Telescope took this close-up of the red planet Mars when it was just 55 million miles – 88 million kilometers – away. This color image was assembled from a series of exposures taken within 36 hours of the Mars closest approach with Hubble's Wide Field and Planetary Camera 2. Mars will be closest to Earth on December 18, at 11:45 p.m. Universal Time (6:45 p.m. EST).
Mars and Earth have a "close encounter" about every 26 months. These periodic encounters are due to the differences in the two planets' orbits. Earth goes around the Sun twice as fast as Mars, lapping the Red Planet about every two years. Both planets have elliptical orbits, so their close encounters are not always at the same distance. In its close encounter with Earth in 2003, for example, Mars was about 20 million miles closer than it is in the 2007 closest approach, resulting in a much larger image of Mars as viewed from Earth in 2003.
The two dominant dark swatches seen just south of the equator on this part of the planet are well observed regions that were originally labeled by early Mars observers. The large triangular shape to the right is Syrtis Major. The horizontal lane to the left is Sinus Meridani. One of NASA's Mars Exploration Rovers, named "Opportunity," landed at the western end of this region in January 2004. At the intersection of these two features is the prominent Huygens crater with a diameter of 270 miles (450 kilometers). South of Huygens is the Hellas impact basin, with a diameter of 1,100 miles (1,760 km) and a depth of nearly 5 miles (8 km). Hellas was formed billions of years ago when an asteroid collided into the Mars surface.
The planet appears free of any dust storms during this closest approach, however, there are significant clouds visible in both the northern and southern polar cap regions. The resolution is 13 miles (21 kilometers) per pixel.
Credits
NASA, ESA, the Hubble Heritage Team (STScI/AURA), J. Bell (Cornell University), and M. Wolff (Space Science Institute, Boulder)| About The Object | |
|---|---|
| Object Name | Mars |
| Object Description | Planet |
| Distance | Distance from the Sun: The semi-major axis of Mars' orbit about the sun is 1.52 Astronomical Units (A.U.) or 142 million miles (228 million km). Distance from the Earth: At the December 18, 2007 closest approach, Mars was 55 million miles (88 million kilometers) from Earth. |
| About The Data | |
| Data Description | This image was created from the HST proposal : K. Noll (The Hubble Heritage Team, STScI), J. Bell III (Cornell Univ.), M. Wolff (Space Science Institute), H. Bond, C. Christian, L. Frattare, F. Hamilton, Z. Levay, M. Mutchler, and W. Januszewski (Hubble Heritage Team, STScI). |
| Instrument | HST>WFPC2 |
| Exposure Dates | December 17, 2007 |
| Filters | F410M (410 nm), F502N (502 nm), and F631N (631 nm) |
| About The Image | |
| Color Info | Blue: F410M Green: F502N Red: F631N |
| Compass Image |  |
| About The Object | |
|---|---|
| Object Name | A name or catalog number that astronomers use to identify an astronomical object. |
| Object Description | The type of astronomical object. |
| R.A. Position | Right ascension – analogous to longitude – is one component of an object's position. |
| Dec. Position | Declination – analogous to latitude – is one component of an object's position. |
| Constellation | One of 88 recognized regions of the celestial sphere in which the object appears. |
| Distance | The physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs. |
| Dimensions | The physical size of the object or the apparent angle it subtends on the sky. |
| About The Data | |
| Data Description |
|
| Instrument | The science instrument used to produce the data. |
| Exposure Dates | The date(s) that the telescope made its observations and the total exposure time. |
| Filters | The camera filters that were used in the science observations. |
| About The Image | |
| Image Credit | The primary individuals and institutions responsible for the content. |
| Publication Date | The date and time the release content became public. |
| Color Info | A brief description of the methods used to convert telescope data into the color image being presented. |
| Orientation | The rotation of the image on the sky with respect to the north pole of the celestial sphere. |
