By Dr. Ethan Siegel -- When you think about the four rocky planets in our Solar System—Mercury, Venus, Earth and Mars—you probably think about them in that exact order: sorted by their distance from the Sun. It wouldn't surprise you all that much to learn that the surface of Mercury reaches daytime temperatures of up to 800 °F (430 °C), while the surface of Mars never gets hotter than 70 °F (20 °C) during summer at the equator.
By Dr. Ethan Siegel -- Here on Earth, the sun provides us with the vast majority of our energy, striking the top of the atmosphere with up to 1,000 Watts of power per square meter, albeit highly dependent on the sunlight's angle-of-incidence. But remember that the sun is a whopping 150 million kilometers away, and sends an equal amount of radiation in all directions; the Earth-facing direction is nothing special. Even considering sunspots, solar flares, and long-and-short term variations in solar irradiance, the sun's energy output is always constant to about one-part-in-1,000.
The answer has everything to do with falling flat on your face (0:54)
Have you watched COSMOS: A Spacetime Odyssey, hosted by astrophysicist Neil deGrasse Tyson? The National Academies Press has put together the Cosmos collection of supplementary materials to go along with the TV program. The books are available for free download.
By Alex H. Kasprak -- Flying over 1300 kilometers above Earth, the Jason 2 satellite knows its distance from the ocean down to a matter of centimeters, allowing for the creation of detailed maps of the ocean’s surface. This information is invaluable to oceanographers and climate scientists. By understanding the ocean’s complex topography—its barely perceptible hills and troughs—these scientists can monitor the pace of sea level rise, unravel the intricacies of ocean currents, and project the effects of future climate change.
From the Royal Astronomical Society -- A meteorite with the mass of a small car crashed into the Moon last September, according to Spanish astronomers. The impact, the biggest seen to date, produced a bright flash and would have been easy to spot from the Earth. The scientists publish their description of the event in the journal Monthly Notices of the Royal Astronomical Society.
By Dr. Ethan Siegel -- Although Saturn has been known as long as humans have been watching the night sky, it's only since the invention of the telescope that we've learned about the rings and moons of this giant, gaseous world. You might know that the largest of Saturn's moons is Titan, the second largest moon in the entire Solar System, discovered by Christiaan Huygens in 1655.
From NPR -- Take a close look at the image below showing a newly formed impact crater on Mars: The blue streaks of material, known as ejecta, radiate 9 miles from the 100-foot crater, according to NASA. The picture was taken from orbit by the on Nov. 19. The same area was imaged by the MRO's Context Camera in July 2010 and again in May 2012 — with no crater in the first and a telltale surface scar in the second.