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What Color is the Red Planet, Really?
Sounds like a trick question, doesn’t it? Sort of like “Who is buried in Grant’s Tomb?” And yet the answer keeps confounding a lot of smart people. (DISCOVER even published a whole feature on the question.) Now the issue keeps coming up again in the latest images from the Curiosity rover. Blue skies on Mars? Can that be right? Which of these images shows what Mars really looks like?
Is this the real Mars? A mosaic from NASA’s Curiosity rover shows Mount Sharp in raw color. NASA describes raw color as the way the scene would look “in a typical smart-phone camera photo.” (Credit: NASA/JPL-Caltech/MSSS)
The very first Viking images from the surface of Mars in July, 1976 showed blue skies, largely because that’s what people were expecting and so that is how the imaging experts initially set the color balance. They quickly realized their error and reissued the image with tangerine skies.
Or is this the real Mars? The scene has been given a white-balanced color adjustment that turns the sky blue. That change simulates Earth-like lighting, making it easier to interpret the geology. (Credit: NASA/JPL-Caltech/MSSS)
Observed: The Day the Universe Lit Up
Although it was born in the fireball brilliance of the Big Bang, the universe spent much of its infancy in the dark. Clouds of primordial particles expanded and cooled forming atoms–hydrogen, mostly that were opaque to light. Galaxies did not yet exist. Even stars did not yet exist. These are known as the cosmic Dark Ages. That era is shrouded in mystery, since scientists literally cannot see what was happening then.
Then gravity did its work. Gas collapsed into bright stars, larger clumpings of matter collected into proto-galaxies, and the universe began to light up. Astronomers have worked out the general theory of how this probably happened. Now at last they are seeing it for real, due to data coming from the brand-new Atacama Large Millimeter/submillimeter Array, or ALMA.
First light: The red blobs are newly discovered, extremely distant galaxies that are forming new stars at a furious rate. They are invisible to ordinary telescopes but easily detectable to ALMA. The blue objects are relatively nearby galaxies, whose gravity is magnifying the radiation from the faraway ones (Credit: ALMA/ESO/NRAO/NAOJ, J. Vieira et al.)
My friend Govert Schilling has written a great explainer about what ALMA is and how it works. This telescope array in Chile’s Atacama desert is a remarkable tool for exploring deep space–so remarkable that it has just yielded groundbreaking work on the Dark Ages even while it is still under construction. Read More
The Difference Between Earth and Moon, in Two Simple Images
NASA’s Solar Dynamics Observatory has been monitoring the sun in detail since its launch in February 2010. Its primary goal is to understand solar variability and improve our ability to forecast it, a capability that has the potential to avert serious blackouts, satellite damage, and interruptions to GPS and radio communications. As a side benefit, though, the observatory produces some great scientific art–like this lovely pair of solar eclipse images.
NASA’s Solar Dynamics Observatory observed the moon partially eclipsing the sun on March 11 at 8:00 a.m. EDT. (Credit: NASA/SDO)
The first shows the sun blotted out by the moon. Note the size of the moon, defined by its curved outline, and the crisp edge. That sharpness is what you see when an airless body passes in front of the sun. All you get is the hard shadow of light blocked by a big spherical ball of rock. On this scale, all the craters and mountains on the moon are insignificant compared to the moon’s overall tidy roundness. The Solar Dynamics Observatory circles 23,000 miles from the Earth (a distance at which it orbits our planet exactly once a day) and about 215,000 miles from the moon in this image. The moon therefore looks roughly the same size as the sun. In reality, it is 400 times smaller, but also more than 400 times closer. Read More
Taking the Very Long View: Cassini Spacecraft Spots Venus…from Saturn
Robotic spacecraft have done an amazing job of expanding human understanding of the worlds of the solar system, and few have done more to aid the cause than the Cassini probe that has been orbiting Saturn since June 30, 2004. Among its astonishing discoveries: lakes of frozen natural gas on Titan, icy geysers on Enceladus, and bizarre hexagonal storms circling Saturn’s north pole. DISCOVER recently featured a guided tour of Cassini pictures, curated by the mission’s top imaging expert, Carolyn Porco.
Venus is the speck of light behind Saturn’s rings, which look odd because they are lit from behind. Cassini was 500,000 miles from Saturn when it took this image. Venus was nearly a billion miles away. (Credit: NASA/JPL-Caltech/Space Science Institute)
But humanity’s far-flung emissaries have not just explored other worlds; they have also provided new perspectives on our place in space, by staring across the vast geometry of our entire solar system. The latest example of this stunning achievement: A new image of Venus taken from Saturn. Read More
Can Dennis Tito Really Get to Mars for $1 Billion?
Dennis Tito’s bombshell announcement that he wants to fly two passengers to Mars–with the mission taking off in less than five years, on January 5, 2018–provoked a lot of intense reactions. Many people were astonished. Many were inspired. Many were deeply skeptical. I was on Fox News yesterday talking with Shepard Smith (the clip is here), who dismissed the idea as “hogwash”; many NASA insiders are more quietly expressing similar levels of skepticism about Tito’s plans.
Artist’s conception of the Inspiration Mars mission, including an inflatable crew module, passing Mars in August, 2018. (Credit: Inspiration Mars Foundation)
So let’s break it down and look at the four key questions about the proposed Inspiration Mars mission. Read More
The Case for Building a Death Star
I got a call yesterday from a producer at Fox News, who asked me if I wanted to comment on a proposal by two California physicists to build a “Death Star” that would protect our planet from incoming asteroids. The answer to a question like that is inevitably going to be “Of course!” so I appeared on Fox News earlier this morning to discuss the idea. (View the story here.)
Conceptual illustration shows how DE-STAR could vaporize an asteroid and power a space probe at the same time…if we could ever build such a thing. (Credit: Philip M. Lubin)
The proposal, which was announced by press release and press conference, comes from cosmologist Philip Lubin of the University of California at Santa Barbara and engineer Gary Hughes of California Polytechnic State University. Calling it a Death Star immediately makes the idea sound both sexy and goofy. The researchers use the term Directed Energy Solar Targeting of Asteroids and exploRation (DE-STAR), which isn’t much better. Setting aside the name, though, the idea is interesting. Read More
Feds: Finding an Incoming Asteroid is 1/20,000th as Important as Homeland Security
One effective way to measure the priorities of the U.S. government is to look at where it directs spending. So in the aftermath of the close passage of asteroid 2012 DA and the much more frightening (and impactful, in the literal sense) aerial impact of a large meteor over Russia, I took a look back at how funding goes to the detection of potentially harmful asteroids. The short answer: amazingly little.
Trail of the large meteor, or bolide, that hit above Chelyabinsk, Russia. (Credit: Nikita Plekhanov)
The leading ground-based search for new potentially hazardous asteroids is the Catalina Sky Survey at the University of Arizona, currently the recipient of a $4.1 million, three-year NASA grant to upgrade its facilities. NASA is also directing $5 million over the next five years to build up the new Asteroid Terrestrial-impact Last Alert System (ATLAS) at the University of Hawaii. Combined with some other, smaller grants to existing programs and to data analysis from older projects, the total comes to about $3 million a year. (It is hard to extract an exact number here, since “asteroid detection” is not broken out as a discrete federal funding category.) Read More
Update: Russian Meteor Was Even Bigger, Rarer Than First Estimated
Reports are still coming in about the brilliant meteor (technically known as a bolide) that slammed into the atmosphere over Russia, causing injuries that sent hundreds of people to the hospital. In any breaking story like this, not all of the information is reliable and details keep getting updated as more facts come in. Here’s the latest.
Debris area of the meteor that struck the atmosphere over Chelyabinsk, Russia, at 3:20 UTC on February 15. (Credit: Google Earth, NASA/JPL-Caltech)
* No, it was not related to asteroid 2012 DA, which streaked close past the Earth earlier today. As strange as it sounds, the Russian event seems to have been coincidental. The observed path of the Russian bolide was totally different than the path of 2012 DA. Read More
Remembering the First Meteorite Injury in the United States
While many other writers–including Discover’s own Keith Kloor and Tom Yulsman–have posted updates on the meteor that exploded over Russia, injuring up to 1,000 people, I was reminded of the first (and so far, only) serious meteorite injury in the United States.
The Hodges Meteorite, the only space rock ever to injure someone in the United States.(Credit: Photo by Beverly Crider)
On November 30, 1954, Ann Elizabeth Hodges of Sylacauga, Alabama, was struck on the hip while sleeping on her sofa. A meteorite had crashed through the roof, bounced off an old-fashioned Philco console radio, and hit her in the abdomen, causing a serious bruise. The meteorite is now commonly known as the Hodges Meteorite in her honor, although it’s one that she undoubtedly would have been just as happy to do without. Hodges was left with lifelong injuries as a result. The Decatur Daily News has a good, detailed reminiscence of the event, as does the University of Alabama.
Meanwhile, The Guardian has a helpful FAQ about today’s Russian meteor explosion, and I have updated my recent blog post about today’s flyby of asteroid 2012 DA–apparently entirely unrelated to the Russian event–and the true risks of being killed by a meteorite, including the latest news. Despite the feeling today that the sky is falling, the danger is still very very small.
The Most Important Thing You Need to Know About the 2/15 Asteroid Flyby
You are not going to die.
A NASA diagram depicting the passage of asteroid 2012 DA14 past the Earth on February 15, 2013. (Credit: NASA/JPL-Caltech)
Fear of death is, of course, the most exciting thing about asteroids. But the asteroid known as 2012 DA is not going to hit the Earth tomorrow. Oh, it will pass close—about 17,150 miles away at 2:25PM EST, closer than many of our communications satellites—but the odds of a collision are zero. Zilch. Nada. (As my friend Phil Plait has just pointed out, we also are not going to be hit by a different asteroid in 2106.) We know the orbit of 2012 DA very precisely, so this is one of life’s rare sure things. ** But see update below. Read More
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