The Rose of Saturn

Recently, NASA release an incredible photo of Saturn’s north pole showing a massive spinning vortex of a storm they dubbed “The Rose”. This false-color image taken by the Cassini spacecraft shows the storm spanning a 2,000 km diameter which, by comparison, is 200 km wider than Hurricane Sandy. Maximum wind speeds of 530 km/h have been calculated—that is some hurricane!
   See how much you know about the ringed planet by answering these ten quiz questions, below. Good luck!

Asteroids

Asteroids have been making quite a few headlines as of late. Recently, we had NASA announcing its intentions to capture and asteroid robotically and bring it back for study by a manned expedition. The ten-year, $2.6 billion project would partner with private companies to capture a 500-ton, near-Earth asteroid that would be bagged, brought back, and placed in a gravitational parking lot known as the Earth-Moon lagrangian point (L2). There, a manned outpost could study it and set up a mining station to harvest its resources, especially its trapped water. Considering that it currently costs $10,000 per pound to haul water into orbit, mining it from an asteroid could save a billion dollars at current launch prices. Add to that the ability to use water to create rocket fuel by splitting it into its elemental components hydrogen and oxygen, it's no surprise that water is also called "space gold".
   On February 15, 2013, a meteor exploded over Russia’s Ural mountains in the Chelyabinsk region, injuring about a thousand people, as the shockwave blew out windows and rocked buildings. On that same day, there was a close flyby of asteroid 2012 DA14, which passed within about 27,000 km of Earth which is closer than the orbits of television and weather satellites that surround our planet. The two events were unrelated. 

Ceres, the largest asteroid
and also a dwarf planet.

   In the weeks after these events, there’s been a renewed call for creating an asteroid detection system. As it stands now, all anyone could do if we discovered a large asteroid headed toward New York City or some other large metropolitan area is “pray,” according to NASA chief Charles Bolden. We only know the whereabouts of about 10% of the estimated 10,000 city-killer asteroids. The Chelyabinsk asteroid is the largest to hit Earth since the 1908 Tunguska asteroid exploded over Siberia, leveling 80 million trees over an area of around 2,100 sq km.
   The asteroid belt lies between the orbits of Jupiter and Mars. Even though there are asteroids in other parts of the solar system, most are found here. About half the mass of the belt is contained in the four biggest asteroids: Ceres, Vesta, Pallas and Hygiea. These have average diameters of more than 400 km, while Ceres, which is also a dwarf planet, has a diameter of about 950 km. The remaining asteroids are thinly distributed and range all the way down in size to dust particles.

Vesta as imaged by the Dawn spacecraft.

   Asteroids are rocky. Because they come from the inner solar system, any ice would have been baked off by the sun long ago. Their orbits are fairly predictable, so with good observations, we can track down the big ones and determine if they’re threats.
   There are more objects beyond Neptune. The Kuiper Belt extends more than 100 times farther from the Sun than Earth. Beyond that is the Oort Cloud which extends 10,000 times farther from the Sun than Earth. These collections of small, icy bodies are remnants from the formation of the solar system. When their orbits are disturbed by other objects they can move into the inner solar system, becoming comets. As they come close to the sun that ice evaporates and creates the comet’s tail. They are less dense than asteroids, and tend to be moving faster by the time they reach the inner solar system. Some comets, like Halley’s comet which returns every 76 years, have predictable, periodic orbits.
   Knowing where an object comes from is a good indicator as to whether it is an asteroid or a comet. It’s not all black-and-white—objects from the outer solar system might be rocky and some asteroids do have some ice. But overall this is good way of thinking about them.

All Eyes on ISON

Comet C/2012 S1 (ISON) shares many of the same
characteristics as the Great Comet of 1680.

Be sure to keep tabs on comet C/2012 S1 (ISON), which is hurling toward a close approach with the sun this fall. Even though ISON is still a long way away, located just inside Jupiter’s orbit, it has already formed a tail of gas and dust stretching 90,000 km.
   This is thought to be the comet’s first pass into the inner solar system and promises to provide us with a spectacular show between November 2013 and January 2014 after it has its close encounter with the Sun.
   C/2012 S1 was discovered in September 2012 by two amateur astronomers using the International Scientific Optical Network in Russia, hence the nickname ISON has been adopted by the media.
   ISON has been recently observed by NASA’s Deep Impact spacecraft. Deep Impact, which was launched in January 2005, was originally used to study comet Tempel 1 by hitting the comet with a small metal probe then doing a close flyby to study the debris it kicked up. In 2010, Deep Impact flew past comet Hartley 2 and is now on its way to a January 2020 visit to a near-Earth asteroid that is large enough and close enough to us to be classified as a potentially hazardous object (PHO) by NASA.
   C/2012 S1 will be well placed for observers in the northern hemisphere during the last two weeks in December 2013. Some speculate that if it does not break up as it reaches perihelion it could become brighter than the moon at its peak, but many sungrazing comets do not survive the encounter. It has been calculated that as it nears the Sun it will reach a peak temperature or 2,700°C, hot enough to melt iron. 
   ISON’s orbital path is similar to that of the Great Comet of 1680, another sungrazer that is also known as Newton’s Comet because Isaac Newton used it to verify Kepler’s laws of planetary motion. Newton’s Comet was one of the brightest comets of the 17th century. It was noted for its extremely long tail and at its peak it was bright enough to be seen during the day. Time will tell if ISON will someday be known as the Great Comet of 2013.

Dangers of a Vacuum

The vacuum chamber that Jim LeBlanc was in
when his spacesuit lost all pressure.

Recently, a reader asked “What happens to the human body in a vacuum? For example, if an astronaut removed his space suit.”
   This reminds me of a scene from the movie 2001: A Space Odyssey. In the movie, HAL has figured out that Dave is planning to disconnect him when he returns to the ship, so he refuses to let Dave back in. Dave is forced to go in through the unpressurized emergency airlock, but there’s a problem: he doesn’t have his space helmet. 

  Terrifying, but Kubrick got the science right. Short-term exposure to the vacuum of space would not make your body explode or freeze solid as some movies have depicted. If you don’t try to hold your breath, exposure to space for about 15 seconds would cause no permanent injury. Holding your breath would be bad, though, because in a vacuum your lungs collect gas from your bloodstream and expands with the drop in pressure. Holding your breath would cause your lungs to overinflate and possibly rupture. This is similar to how scuba divers need to exhale when rising to the surface or risk damaging their lungs. 
   Temperature would not be an immediate problem because although space is very cold, a vacuum is a perfect insulator. You would only gradually radiate away your body heat. Exposure to direct sunlight would give you a sunburn. Your saliva and tears would quickly evaporate and you might have eardrum troubles.
   After about 15 seconds, oxygen-deprived blood from the lungs reaches the brain causing you to lose consciousness. 
   At such low pressures, your body fluids will boil away. Moist surfaces such as the eyes, mouth and airways experience this immediately. Fluids inside your body also start to vaporize. This happens rapidly in the lungs and under the skin. Bubbles of water vapor that form in the bloodstream will interrupt the circulation. This is called ebullism. No one knows how long the human body can withstand the vacuum of space—perhaps a couple of minutes. 
   In 1965, this actually happened to Jim LeBlanc while working at the NASA Manned Spacecraft Center (now called the Johnson Space Center). He was testing a space suit in their vacuum chamber when the tube that was pressurizing his suite came loose and his suit was almost completely depressurized within seconds. He stayed conscious for about 14 seconds and they began repressurizing the chamber right after he passed out. After regaining consciousness, he recalled that he could hear and feel the air leaking out of his suit, and the last thing he remembered was the saliva on his tongue starting to boil.

NASA Takes Gold in the 567 Billion Meter Dash!

The first image taken by the NASA Curiosity rover after
the dust covers were removed from the cameras.

I watched in amazement last night as NASA pulled off a perfect landing to put Curiosity—the most complex rover ever built—on the Martian surface. Congratulations to all the hard-working men and women at NASA/JPL for not creating a 2.5 billion dollar crater instead! If they were terrified during those seven minutes from when Curiosity entered the Martian atmosphere travelling 20,000 kph until touchdown, I sure could not tell. Nothing but professionalism and ear to ear grins and high fives once it had landed. 
   Curiosity weighs in at 900 kg and is three meters long, larger than some small cars. It is equipped with 80 kg of instrumentation, including a variety of cameras and a laser that is powerful enough to vaporize rock. These are the most-advanced instruments ever used on the Martian surface. Curiosity will be able to determine mineral and soil composition, atmospheric processes, detect chemical biosignatures and characterize the surface radiation on Mars.
   The Mars Science Laboratory’s goals for this mission are to search Mars for signs of life, past or present, study the climate and geology of Mars, and plan for a future manned mission to Mars. The mission is scheduled to last for about two years, but if conditions are favorable, the rover could be in operation for much longer.
   In the weeks and months to come I will be writing more about this incredible mission and its discoveries. In the meantime, to celebrate NASA/JPL’s successfully landing, this week’s quiz is about Mars. See how much you know about the Red Planet.