NASA has released a free-air gravity map of the Moon: “If the Moon were a perfectly smooth sphere of uniform density, the gravity map would be a single, featureless color, indicating that the force of gravity at a given elevation was the same everywhere. But like other rocky bodies in the solar system, including Earth, the Moon has both a bumpy surface and a lumpy interior. … The free-air gravity map shows deviations from the mean, the gravity that a cueball Moon would have.” Gravity data comes from the GRAIL mission, with the digital elevation model provided by the Lunar Reconnaissance Orbiter laser altimeter. Image credit: NASA’s Goddard Goddard Space Flight Center Scientific Visualization Studio.
Tag: NASA
Mapping the Heat Wave
Hotter than usual? Yes. This map shows how much land surface temperatures during the week of June 17-24, 2012 have been above or below the average for 2000-2011. Now this map measures something very specific: land surface temperatures (LSTs) aren’t the same as air temperatures: “LSTs indicate how hot the surface of the Earth would feel to the touch. From a satellite vantage point, the ‘surface’ includes a number of materials that capture and retain heat, such as desert sand, the dark roof of a building, or the pavement of a road. As a result, daytime land surface temperatures are usually higher than air temperatures.” Via Bad Astronomy.
Perpetual Ocean
You may have seen this already: a beautiful, painting-like visualization of the world’s surface ocean currents between June 2005 and November 2007, which NASA posted last month. The visualization is based on model data from the ECCO2 project. See also this short video on Flickr (Flash required). Image credit: NASA/
A Map of Rising Global Temperatures
This animated map from NASA (Flash-only, sorry) illustrates global temperatures since 1880: “reds indicate temperatures higher than the average during a baseline period of 1951-1980, while blues indicate lower temperatures than the baseline average.” News flash: the planet’s getting warmer. More information here.
Previously: Global Temperature Changes by Decade.
A New Lunar Topo Map
A new topographic map of the Moon from the Lunar Reconnaissance Orbiter: “Today the LROC team releases Version 1 of the Wide Angle Camera (WAC) topographic map of the Moon. This amazing map shows you the ups and downs over nearly the entire Moon, at a scale of 100 meters across the surface, and 20 meters or better vertically.” Late last year lunar topo maps were released that were based on laser altimeter data; presumably the WAC data, based on stereo observations, is better. Image credit: NASA/