It seems the sky is falling…

Imagine driving in your car on a lovely Friday morning and seeing a flaming ball of death streaking across the sky and coming, as best you can tell, right at you.

This view from a Russian dashboard camera shows a terrifying view of the fireball as the meteoroid entered the atmosphere and hurtled over the city of Chelyabinsk. Credit: Discovery News

That’s what terrified citizens in the lovely Russian city of Chelyabinsk experienced on the morning of Friday, February 15. The multitude of videos and photos of this meteor are simply horrifying since many of them give the impression that this huge chunk of flaming interplanetary death is about to smash right into the camera. Not only did this fireball make a scary visual impression, but it packed a very literal punch as well. As the meteoroid hurtled through the atmosphere at 40,000 mph, the heat and pressure it felt caused it to break apart with a huge amount of energy, the equivalent of 470 kilotons of TNT (or 30-40 times the power of the atomic bomb dropped on Hiroshima). The deposition of that huge amount of energy into the sky caused a pressure wave that blasted the city. Over 1,000 people were injured by the blast, mostly due to cuts and scrapes from glass as windows shattered. Scientists have now come to the conclusion that the initial object was only 17 meters wide– that’s about the size of a tractor trailer. That’s pretty small cosmically speaking. Imagine the damage that could have been inflicted if something larger had hit the atmosphere. The last time a meteor had significant large-scale impact was in 1908, again in Russia. This impact, known as the “Tunguska event“, is the largest impact ever recorded- 20-30 times larger than the one that happened this month. This meteoroid, which is estimated to have been about 100 meters wide (the size of a football field), blew up in the air and released 10-15 megatons of energy, leveling 830 square miles of trees. Witnesses to the event said that the heat and pressure from the explosion made their skin feel like it was on fire.

The 1908 Tunguska event, the largest impact near or on Earth ever recorded, leveled trees over 830 square miles. Credit: nightsky.org

Luckily the 2013 Russian meteor was much smaller, so windows got knocked out but buildings weren’t leveled. The object was actually so small that astronomers didn’t even see it coming. NASA has a whole division of people who track objects that could potentially come close to Earth, it’s known as the Near-Earth Object Program. Unfortunately, for scientists to be able to see an object it needs to be large enough to reflect an observable amount of light. That didn’t happen here.

The meteor also came as a bit of a shock since scientists were so focused on another Near-Earth Object called 2012 DA14. This 45-meter wide asteroid was scheduled for a flyby of Earth on the same day, February 15. This relatively small piece of space rock flew closer to the Earth than any other celestial body. It was 17,200 miles away at its closest approach, that’s closer than satellites in geosynchronous orbit and much, much closer than the Moon. Although scientists were certain that DA14 wouldn’t impact the Earth, they were very excited to use the close flyby as an opportunity to study the asteroid.

This collage of 72 individual radar-generated images of asteroid 2012 DA14 was created using data from NASA’s 230-foot Deep Space Network antenna at Goldstone, CA. Credit: NASA

Of course it was ironic that after weeks of assuring the public that there was no threat of an impact from DA14 another huge impact happened in Russia the same day. Scientists from NASA’s Meteoroid Environment Office concluded that the Russian meteor and DA14 were totally unrelated, having come from two very distinct trajectories/orbits. This means it was a huge cosmic coincidence that they just happened to occur on the same day…weird.

This plot of the orbits of the Russian meteor and asteroid 2012 DA14 show that the two bodies came from very different parts of the solar system and were unrelated. The Russian meteoroid most likely originated from the Asteroid Belt out past Mars. Credit: NASA/Space.com

Earth is not alone…

Continuing the lunar trend after my last post, which highlighted new multimedia from NASA that reviewed the stages of the Moon’s development and a tour of the Moon’s most notable features, now I’d like to share some more recent news about Earth’s only natural satellite…or so we thought.

Leading theories about the creation of the Moon is that an object about half the size of Earth (roughly Mars-sized) collided with the Earth roughly 4.5 billion years ago. This cataclysmic, near-Earth-ending impact (models show that an impactor only 10% larger would have completely destroyed the planet) ejected a large amount of debris that settled into a ring system around Earth. As the Earth cooled and gravity pulled the planet’s mass into its roughly spherical shape (technically an “oblate spheroid“), pieces of debris in that ring system began to collide and combine, eventually collecting almost all of the debris and forming the Moon. But now, as NPR reports, an international collaboration of researchers from the University of Hawaii, University of Finland, and Observatoire de Paris have written a computer simulation that calculates how many small asteroid-like objects may actually be in captured orbits around Earth. Their results, published in a recent issue of the scientific journal Icarus, conclude that at any given time, Earth may have one or more smaller captured objects, or additional “moons”, in orbit around it. The idea of a captured moon is not a new one, most scientists agree that the two irregularly-shaped moons of Mars, Phobos and Deimos, are most likely captured asteroids whose orbits were disturbed while out in the asteroid belt and were captured by the Red Planet after they strayed too close to it. And of course having a single moon would make Earth unique, of the 6 planets which have moons (Mercury and Venus lack them), Earth is the only planet with a singular moon, or so we thought. But even if these other natural satellites are in orbit around earth, will we consider them moons or will the International Astronomical Union (IAU) make some new kind of classification of “dwarf moons”?

The moons of Mars, Phobos (left) and Deimos (right) are thought to be captured asteroids. Credit: Encylcopedia Britannica

Speaking of the good ol’ IAU, as I detailed in one of my earliest posts, “Alas, poor Pluto“, part of the 2006 decision that de-planetized Pluto defined that a “planet” must clear its orbit of debris. I also mentioned that such a vague definition could leave open an argument for Jupiter to be demoted as well since it has Trojan asteroids which share its orbit. Well now, some could argue that Earth might not technically be a planet anymore either. A new study by NASA’s Wide-field Infrared Survey Explorer (WISE) mission located a Trojan asteroid that shares Earth’s orbit. As NASA explains, “Trojans are asteroids that share an orbit with a planet near stable points in front of or behind the planet. Because they constantly lead or follow in the same orbit as the planet, they never can collide with it. In our solar system, Trojans also share orbits with Neptune, Mars and Jupiter. Two of Saturn’s moons share orbits with Trojans.” Details about the tiny Trojan, designated 2010 TK7, were published in the July 28 issue of Nature. 2010 TK7, seen in the star field below, is only 1,000 feet (300 meters) in diameter is in a highly irregular orbit as it follows Earth around the Sun (click here for an animation of the little guy’s odd orbit). Thankfully though, the smart folks at NASA have done their research and the asteroid’s orbit is well-defined and for at least the next 100 years, so we know that it will not come closer to Earth than 15 million miles (24 million kilometers), which is more than 50 times the distance from the Earth to the Moon. So no end of the world asteroid impacts…from this asteroid, but I’ll leave that conversation for another post.

Earth’s only known Trojan asteroid, 2010 TK7, is shown here, in the green circle, among a field of stars. The asteroid was found by NASA’s WISE mission. Credit: NASA

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Hello Moon, Hello Einstein…

The Moon as imaged by UNH Observatory volunteer and local amateur astronomer, John S. Gianforte of Blue Sky Observatory. You can check out more of John’s amazing astrophotography at www.theskyguy.org.

NASA’s Lunar Reconnaissance Orbiter (LRO) launched back in June 2009 to start its mission of reinvestigating Earth’s only natural satellite. LRO was also launched with its companion mission Lunar CRater Observation and Sensing Satellite (LCROSS) which generated a lot of press coverage about NASA bombing the Moon. As the official LRO website explains, “The LRO instruments return global data, such as day-night temperature maps, a global geodetic grid, high resolution color imaging and the moon’s UV albedo. However there is particular emphasis on the polar regions of the moon where continuous access to solar illumination may be possible and the prospect of water in the permanently shadowed regions at the poles may exist.” So basically LRO is our first step in finding out more about the Moon to help inform decisions about when, where, and how we might go back there. “LRO follows in the footsteps of the predecessors to the Apollo missions – missions designed in part to search for the best possible landing sites (such as the Ranger, Lunar Orbiter and Surveyor missions). However, building a lunar outpost implies extended periods on the lunar surface and so the goals of LRO go beyond the requirements of these previous missions. LRO focuses on the selection of safe landing sites, identification of lunar resources, and the study of how the lunar radiation environment will affect humans.” In fact, researchers right here at UNH have an instrument called Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on LRO which is essentially testing the dosage of harmful cosmic radiation that the moon (and future human colonizers or visitors) would be exposed to.

In honor of reaching 1,000 days in orbit around the Moon, the LRO team at NASA Goddard Space Flight Center in Greenbelt, MD has released two new videos about Earth’s celestial companion. The first video, “Evolution of the Moon” takes viewers through a very interesting visually stimulating history of the moon’s evolution, and reveals how it came to appear the way it does today. The second video, “Tour of the Moon”, gives viewers a guided looks-too-amazing-to-be-real tour of prominent locations on the moon’s surface, compiled by the spacecraft’s observations of the moon. If you’ve got a few minutes (~7) to spare, you can check out both of the movies combined here: Evolution and Tour of the Moon.

Also, just a quick reminder that today, March 14, 2012 marks the 133rd birthday of Albert Einstein (seen below), arguably the most influential and probably most popular scientist of the last century (possibly of all time). Remembered for his famous equation regarding mass-energy conservation (E=mc²), his multitude of inspirational and often humorous quotes, zany hairdo, and all-around joviality, Einstein reached a level of celebrity unknown to scientists before him and unparalleled by most since. Although most famous for his work in developing the theories of special and general relativity, Einstein was actually awarded his only Nobel Prize for Physics in 1921 for a paper from his notoriously prolific annus mirabilis (or extraordinary year) 0f 1905 (when he published four scientific papers, all of which went on to shape the some scope of the basis of modern day physics) that explained the photoelectric effect. This particular paper, “On a Heuristic Viewpoint Concerning the Production and Transformation of Light”, was the first to propose the idea of quantized energy, what would become the basis of all quantum mechanics and most modern technology. If you’d like to find out more about Einstein’s life, I recommend checking out noted biographer Walter Isaacson’s Einstein: His Life and Universe.

Albert Einstein, most commonly known for his famous E=mc² equation, actually won his only Nobel Prize in Physics for his explanation of the photoelectric effect. Credit: hebrewyou.com

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Getting your rocks off…

Hello all you loyal readers out there, sorry for the lack of posts this summer, but it’s just so nice outside and it’s hard to see with the sunlight reflecting off my screen. In any case there’s a lot going on down in Washington regarding budgets and debt and all that good economics stuff (read: things that I don’t really understand or care to), so I figure I’ll just ignore that and talk about some fun space stuff!

  • First off, as this blog has been (or attempting to) chronicling for most of the summer, NASA finally ended the Space Shuttle program after the successful return of the final mission of Atlantis on July 21. The shuttle ran an amazing 30 year history and is still to this day the most sophisticated vehicle ever constructed by man. NASA and the U.S. government now have to wait and hope (with bated breath and some hard finger crossing) that private companies quickly ramp up the development and advancement of private launch capabilities. Several big-time frontrunners in the commercialization of space exploration (SpaceX, Orbital Sciences, etc.) have hit major setbacks, failures, and are going way over budget.
  • Next up, here is a very cool picture from the Opportunity rover on Mars. Yes, that’s right Opportunity found metal on Mars! How cool is that!??!! But yeah, not the giant pieces of scrap metal that are in the background, NASA is actually interested in that strange metallic-looking rock in the foreground to the left. That’s the real prize. The scrap metal (which I  half expected to see wrecked R2-D2 and C-3PO somewhere near…) is not some failed attempt at Martians to reach space, it’s actually Opportunity‘s own heat shielding that was abandoned during the rover’s descent back in 2004. The rock though, found to be made mostly of dense metals iron and nickel, is thought to be just as alien to Mars as Opportunity‘s heat shielding. Scientists believe the rock to be a meteorite much like the vast number found in Antarctica here on Earth.

It’s not the scrap metal here that interests scientists, but the small metallic rock in the left foreground. Credit: APOD

  • In a news story that is too weird to be made up, a man recently released from jail, is finally having the story told of how he stole moon rocks from NASA (similar to the NJ heist?). A new book, Sex on the Moon: The Amazing Story Behind the Most Audacious Heist in History by Ben Mezrich (the author of the books Bringing Down the House and The Accidental Billionaires, the movies behind 21 and The Social Network respectively), focuses on the story of then-24-year-old Thad Roberts, a former Mormon from Utah, who stole an entire safe full (not just the rocks in the safe, but the ENTIRE safe) of moon rocks from a lab at NASA’s Johnson Space Center in Houston back in 2002. Why, you ask, would the wanna-be astronaut pull off such an audacious crime? For the love of a girl he’d met only three weeks prior…so he claims. In any case the article and book detail the robbery and how the couple celebrated the crime on the 33rd anniversary of first moon walk by being intimate ON the rocks (hence the pun of this post’s title). The short summary is, people are weird, but this book HAS to be a page-turner.

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