A hibernating spacecraft has been called back into service. The WISE (Wide-field Infrared Survey Explorer”) spacecraft that has been sleeping in a polar orbit around Earth for two years will be turned back on next month to hunt for more potentially hazardous asteroids, and perhaps search for an asteroid that NASA could capture and explore in the future.
“The WISE mission achieved its mission’s goals and as NEOWISE extended the science even further in its survey of asteroids. NASA is now extending that record of success, which will enhance our ability to find potentially hazardous asteroids, and support the new asteroid initiative,” said John Grunsfeld, NASA’s associate administrator for science. “Reactivating WISE is an excellent example of how we are leveraging existing capabilities across the agency to achieve our goal.”
WISE originally was launched in December 2009 and scanned the entire celestial sky in infrared light about 1.5 times, searching for the coolest stars, the universe’s most luminous galaxies and some of the darkest near-Earth asteroids and comets. It captured more than 2.7 million images of objects in space, ranging from faraway galaxies to asteroids and comets close to Earth.
However, in early October 2010, after completing its prime science mission, the spacecraft ran out of the frozen coolant that keeps its instrumentation cold. But two of its four infrared cameras remained operational, which were still optimal for asteroid hunting, so NASA extended the NEOWISE portion of the WISE mission by four months, with the primary purpose of hunting for more asteroids and comets, and to finish one complete scan of the main asteroid belt.
The NEOWISE mission completed a full sweep of the main asteroid belt, and during 2010, NEOWISE observed about 158,000 rocky bodies out of approximately 600,000 known objects. Discoveries included 21 comets, more than 34,000 asteroids in the main belt between Mars and Jupiter, and 135 near-Earth objects.
“The data collected by NEOWISE two years ago have proven to be a gold mine for the discovery and characterization of the NEO population,” said Lindley Johnson, NASA’s NEOWISE program executive in Washington. “It is important that we accumulate as much of this type of data as possible while the WISE spacecraft remains a viable asset.”
Now WISE will again search for asteroids with a new extra-extended three year mission to search for more PHAs as well as suitable asteroids for future human exploration missions.
NASA said they anticipate WISE will use its 16-inch (40-centimeter) telescope and infrared cameras to discover about 150 previously unknown NEOs and characterize the size, albedo and thermal properties of about 2,000 others — including some of which could be candidates for the agency’s recently announced asteroid initiative.
“The team is ready and after a quick checkout, we’re going to hit the ground running,” said Amy Mainzer, NEOWISE principal investigator at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “NEOWISE not only gives us a better understanding of the asteroids and comets we study directly, but it will help us refine our concepts and mission operation plans for future, space-based near-Earth object cataloging missions.”
During the stationary recovery test of Orion at Norfolk Naval Base on Aug. 15, 2013, US Navy divers attached tow lines and led the test capsule to a flooded well deck on the USS Arlington. Credit: Ken Kremer/kenkremer.com. Story updated with additional test Video and images[/caption]
NAVAL STATION NORFOLK,VA – When American astronauts again venture into deep space sometime in the next decade, their return trip to Mother Earth will end with the splashdown of their Orion capsule in the Pacific Ocean – much like the Apollo lunar landing crews of four decades ago.
But before that can happen, Orion must first pass through a myriad of milestones to insure the safe return of our human crews.
A NASA and U.S. Navy test successfully demonstrated the water recovery of the Orion crew module today (Aug. 15) at Naval Station Norfolk in Virginia – and Universe Today witnessed the entire operation.
“Today’s test was terrific,” Scott Wilson, NASA’s Orion Manager of Production Operations, told Universe Today in a post test interview at Naval Station Norfolk.
“We got all the data we needed and the test was very successful. This was exactly what we wanted to do and we don’t like surprises.”
Today’s ‘Orion Stationary Recovery Test’ was conducted to support the upcoming first flight of Orion on the EFT-1 mission due to blastoff in September 2014 from Cape Canaveral, Florida.
“We completed all of our primary and secondary test objectives,” Wilson stated.
Teams of US Navy divers in a flotilla of amphibious boats launched from the USS Arlington approached a test version of the Orion capsule known as the boilerplate test article (BTA). The Arlington was docked against its pier during the test in a benign, controlled environment.
Divers attached several tow lines to the capsule, in a coordinated operation with the Arlington, and led the capsule into the ship’s flooded well deck.
The Orion capsule was carefully towed inside the well deck and positioned over the recovery cradle. The sea water was drained and the capsule was attached to the recovery cradle.
“During the test there is constant radio communications between the ship and the divers teams in the boats.”
“The operation within the well deck areas are also being controlled as well as the rope and winch handlers on the boat,” Wilson told me.
At the conclusion of the test, myself and the NASA social media participants boarded the USS Arlington and toured the Orion capsule for a thrilling up close look.
“Today marks a significant milestone in the Navy’s partnership with NASA and the Orion Human Space Flight Program,” said Navy Commander Brett Moyes, Future Plans Branch chief, U.S. Fleet in a statement.
“The Navy is excited to support NASA’s continuing mission of space exploration. Our unique capabilities make us an ideal partner for NASA in the recovery of astronauts in the 21st century — just as we did nearly a half century ago in support of America’s quest to put a man on the moon.”
The ocean recovery of Orion will be far different from the Apollo era where the crew’s were first hoisted out of the floating capsule and the capsule then hoisted on deck of a US Navy aircraft carrier.
The next Orion water recovery test will be conducted in the open waters of the Pacific Ocean in January 2014.
NASA’s Langley Research Center in nearby Hampton, VA is conducting an extensive drop test program in support of the Orion project.
“The Orion capsule tested today has the same mold line and dimensions as the Orion EFT-1 capsule.”
“The Orion hardware and the Delta IV Heavy booster for the EFT-1 launch are on target for launch in 2014,” Wilson told me.
Watch this NASA Video of the Orion test:
During the unmanned Orion EFT-1 mission, the capsule will fly on a two orbit test flight to an altitude of 3,600 miles above Earth’s surface, farther than any human spacecraft has gone in 40 years.
The EFT-1 mission will provide engineers with critical data about Orion’s heat shield, flight systems and capabilities to validate designs of the spacecraft before it begins carrying humans to new destinations in the solar system, including an asteroid and Mars.
It will return to Earth at a speed of approximately 20,000 mph for a splashdown in the Pacific Ocean.
Right now its T Minus 1 Year and counting to liftoff of Orion EFT-1.
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Learn more about Orion, Cygnus, Antares, LADEE, MAVEN, Mars rovers and more at Ken’s upcoming presentations
Sep 5/6/16/17: LADEE Lunar & Antares/Cygnus ISS Rocket Launches from Virginia”; Rodeway Inn, Chincoteague, VA, 8 PM
Oct 3: “Curiosity, MAVEN and the Search for Life on Mars – (3-D)”, STAR Astronomy Club, Brookdale Community College & Monmouth Museum, Lincroft, NJ, 8 PM
One scientific team has identified 12 “Easily Retrievable Objects” in our solar system that are circling the sun and would not cost too much to retrieve (in relative terms, of course!)
The definition of an ERO is an object that can be captured and brought back to a stable gravitational point near Earth (called a Lagrange point, or more specifically the L1/L2 points between the sun and the Earth.) The change in speed necessary in these objects to make them easily retrievable is “arbitrarily” set at 500 meters per second (1,641 feet/second) or less, the researchers stated.
Catching the objects wouldn’t just be a technology demonstration, but also could shed some light into how the solar system formed. Asteroids are generally considered leftovers of the early days of the neighborhood; under our current understanding of the solar system’s history, a spinning disc of gas and dust gradually clumped into rocks and other small objects, which eventually crashed into each other and formed planets.
Also, steering these objects around has another benefit: teaching humans how to deflect potentially hazardous asteroids from smacking into the Earth and causing damage. As we were reminded about earlier this year, even smaller rocks such as the one that broke up over a portion of Russia can be hazardous.
There are at least a couple of big limitations to the plan. The first is to make sure not to put the asteroid in a path that would hit the Earth. The second is that he L1 and L2 points are somewhat unstable, so over time the asteroid would drift from its spot. It would need a nudge every so often to keep it in that location.
For the curious, this is the complete list of possible asteroids: 2006 RH120, 2010 VQ98, 2007 UN12, 2010 UE51, 2008 EA9, 2011 UD21, 2009 BD, 2008 UA 202, 2011 BL45, 2011 MD, 2000 SG344 and 1991 VG.
There’s a potential “cometary graveyard” of inactive comets in our solar system wandering between Mars and Jupiter, a new Colombian research paper says. This contradicts a long-standing view that comets originate on the fringes of the solar system, in the Oort Cloud.
Mysteriously, however, 12 active comets have been seen in and around the asteroid belt. The astronomers theorize there must be a number of inactive comets in this region that flare up when a stray gravitational force from Jupiter nudges the comets so that they receive more energy from the Sun.
The researchers examined comets originating from the main asteroid belt between Mars and Jupiter, a spot where it is believed there are only asteroids (small bodies made up mostly of rock). Comets, by contrast, are a mixture of rocks and ice. The ice melts when the comet gets close to the sun, and can form spectacular tails visible from Earth. (Here’s more detail on the difference between a comet and an asteroid.)
“Imagine all these asteroids going around the Sun for aeons, with no hint of activity,” stated Ignacio Ferrín, who led the research and is a part of the University of Antioquia in Colombia.
“We have found that some of these are not dead rocks after all, but are dormant comets that may yet come back to life if the energy that they receive from the Sun increases by a few per cent.”
The team believes this zone was far more active millions of years ago, but as the population got older they got more quiet.
“Twelve of those rocks are true comets that were rejuvenated after their minimum distance from the Sun was reduced a little,” the researchers stated.
“The little extra energy they received from the Sun was then sufficient to revive them from the graveyard.”
It’s still unclear if NASA will receive Congressional funding or authorization to do an asteroid retrieval proposal backed by President Barack Obama’s administration, but as missions take time to plan, the agency is moving ahead with its work for now.
NASA just did a mission formulation review this week to look at some internal studies on the mission. It also is starting to wade through hundreds of ideas the space community submitted concerning the mission.
“With the mission formulation review complete, agency officials now will begin integrating the most highly-rated concepts into an asteroid mission baseline concept to further develop in 2014,” NASA stated. The agency was light on details, but more information should be forthcoming when the process is further along.
The agency’s fiscal 2014 budget proposal suggests robotically picking up an asteroid, steering it closer to Earth, and putting it in a safe orbit where probes and possibly astronauts could visit. The budget is still being moved through Congressional committees and we won’t know until later this year just how much money will be available for NASA, and what initiatives the agency will be allowed to do.
For more information, be sure to read this past article from Universe Today editor Nancy Atkinson looking in detail at NASA’s asteroid retrieval mission. It includes information on what technology could be used, and the history of NASA’s quest to explore asteroids.
Space rocks have hit the headlines several times this year, particularly when one exploded over the area of Chelyabinsk, Russia earlier in 2013. NASA and several other groups have ongoing searches for asteroids and other small bodies in our solar system to catalog and calculate the orbits for as many as they can find. No imminent threats are known.
One of the most fascinating stories in modern astronomy involves the pursuit of a world that never was.
Tomorrow marks the 135th anniversary of the total solar eclipse of July 29th, 1878. With a maximum totality of 3 minutes 11 seconds, this eclipse traced a path across western Canada and the United States from the territory of Montana to Louisiana.
A curious band of astronomers also lay in wait along the path of totality, searching for an elusive world known as Vulcan.
Long before Star Trek or Mr. Spock, Vulcan was a hypothetical world thought to inhabit the region between the planet Mercury and the Sun.
The tale of Vulcan is the story of the birth of modern predictive astronomy. Vulcan was a reality to 18th century astronomers- it can be seen and the astronomy textbooks and contemporary art and culture of the day. Urbain J.J. Le Verrier proposed the existence of the planet in 1859 to explain the anomalous precession of the perihelion of the planet Mercury. Le Verrier was a voice to be taken seriously — he had performed a similar feat of calculation to lead observers to the discovery of the planet Neptune from the Berlin Observatory on the night of September 23, 1846. Almost overnight, Le Verrier had single-handedly boosted astronomy into the realm of a science with real predictive power.
The idea of Vulcan gained traction when a French doctor and amateur astronomer Edmond Lescarbault claimed to have seen the tiny world transit the Sun while viewing it through his 95 millimetre refractor on the sunny afternoon of March 26th, 1859. Keep in mind, this was an era when solar observations were carried out via the hazardous method of viewing the Sun through a smoked or oil-filled filter, or the via safer technique of projecting the disk and sketching it onto a piece of paper.
A visiting Le Verrier was sufficiently impressed by Lescarbault’s observation, and went as far as to calculate and publish orbital tables for Vulcan. Soon, astronomers everywhere were “seeing dots” pass in front of the Sun. Astronomer F. A. R. Russell spotted an object transiting the Sun from London on January, 29th, 1860. Sightings continued over the decades, including a claim by an observer based near Peckeloh Germany to have witnessed a transit of Vulcan on April 4th, 1876.
Incidentally, we are not immune to this effect of “contagious observations” even today — for example, when Comet Holmes brightened to naked eye visibility in October 2007, spurious reports of other comets brightening flooded message boards, and a similar psychological phenomena occurred after amateur astronomer Anthony Wesley recorded an impact on Jupiter in 2010. Though the event that triggered the initial observation was real, the claims of impacts on other bodies in the solar system that soon followed turned out to be bogus.
Still, reports of the planet Vulcan were substantial enough for astronomers to mount an expedition to the territory of Wyoming in an attempt to catch dim Vulcan near the Sun during the brief moments of totality. Participants include Simon Newcomb of the Naval Observatory, James Craig Watson and Lewis Swift. Inventor Thomas Edison was also on hand, stationed at Rawlins, Wyoming hoping to test his new-fangled invention known as a tasimeter to measure the heat of the solar corona.
Conditions were austere, to say the least. Although the teams endured dust storms that nearly threatened to cut their expeditions short, the morning of the 29th dawned, as one newspaper reported, “as slick and clean as a Cheyenne free-lunch table.” Totality began just after 4 PM local, as observers near the tiny town of Separation, Wyoming swung their instruments into action.
Such a quest is difficult under the best of circumstances. Observers had to sweep the area within 3 degrees of the Sun (six times the diameter of a Full Moon) quickly during the fleeting moments of totality with their narrow field refractors, looking for a +4th magnitude star or fainter among the established star fields.
In the end, the expedition was both a success and a failure. Watson & Swift both claimed to have identified a +5th magnitude object similar in brightness to the nearby star Theta Cancri. Astronomer Christian Heinrich Friedrich Peters later cast doubt on the sighting and the whole Vulcan affair, claiming that “I refuse to go on a wild goose chase after Le Verrier’s mythical birds!”
And speaking of birds, Edison ran into another eclipse phenomenon while testing his device, when chickens, fooled by the approaching false dusk came home to roost at the onset of totality!
But such is the life of an eclipse-chaser. Albert Einstein’s general theory of relativity explained the precession of Mercury’s orbit in 1916 and did away with a need for Vulcan entirely.
But is the idea of intra-Mercurial worldlets down for the count?
Amazingly, the quest for objects inside Mercury’s orbit goes on today, and the jury is still out. Dubbed Vulcanoids, modern day hunters still probe the inner solar system for tiny asteroids that may inhabit the region close to the Sun. In 2002, NASA conducted a series of high altitude flights out of the Dryden Flight Research Center at Edwards Air Force Base, California, sweeping the sky near the Sun for Vulcanoids at dawn and dusk. Now, there’s a job to be envious of — an F-18 flying astronomer!
NASA’s MESSENGER spacecraft was also on the lookout for Vulcanoids on its six year trek through the inner solar system prior to orbital insertion on March 18th, 2011.
Thus far, these hunts have turned up naught. But one of the most fascinating quests is still ongoing and being carried out by veteran eclipse-chaser Landon Curt Noll.
Mr. Noll last conducted a sweep for Vulcanoids during total phases of the long duration total solar eclipse of July 22nd, 2009 across the Far East. He uses a deep sky imaging system, taking pictures in the near-IR to accomplish this search. Using this near-IR imaging technique during a total solar eclipse requires a stable platform, and thus performing this feat at sea or via an airborne platform is out. Such a rig has been successful in catching the extremely thin crescent Moon at the moment it reaches New phase.
To date, no convincing Vulcanoid candidates have been found. Mr. Noll also notes that the European Space Agency/NASA’s joint Solar Heliospheric Observatory (SOHO) spacecraft has, for all intents and purposes, eliminated the possibility of Vulcanoids brighter than +8th magnitude near the Sun. Modern searches during eclipses conducted in this fashion scan the sky between wavelengths of 780 to 1100 nanometres down to magnitude +13.5. Mr. Noll told Universe Today that “Our improved orbital models show that objects as small as 50m in diameter could reside in a zone 0.08 A.U. to 0.18 AU (1.2 to 2.7 million kilometers) from the Sun.” He also stated that, “there is plenty of ‘room’ for (Vulcanoids) in the 50 metre to 20 kilometre range.”
Mr. Noll plans to resume his hunt during the August 21st, 2017 total solar eclipse spanning the continental United States. Totality for this eclipse will have a maximum duration of 2 minutes and 40 seconds. Circumstances during the next solar eclipse (a hybrid annular-total crossing central Africa on November 3rd, 2013) will be much more difficult, with a max totality located out to sea of only 1 minute and 40 seconds.
Still, we think it’s amazing that the quest for Vulcan (or at least Vulcanoids) is alive and well and being spearheaded by adventurous and innovative amateur astronomers. In the words of Vulcan’s native fictional son, may it “Live Long & Prosper!”
It takes gumption to go knee-deep in mud to save a stranded rover. Or to climb up precarious slopes in search of the perfect rock. Oh, and did we mention the location is best accessible by air, with no towns nearby?
Take these challenging conditions, which Canadian astronaut Jeremy Hansen faced in the Arctic this month, and then imagine doing this on the moon. Or an asteroid. Or Mars. Scary, isn’t it? But that’s what he’s thinking of and training for as he does geology work a few times a year.
“It’s important; it provides an opportunity in a somewhat uncomfortable, risky situation when we’re doing real science,” Hansen told Universe Today of his time in Haughton Crater in Canada’s north. In fact, it’s so important to Hansen that he’s gone on similar geology trips with this Western University group three times.
There would be vast differences between Earth exploration and heading to another location, however. Some examples:
Water and supplies. The team Hansen joined had nine people and 29 checked bags for an expedition that lasted just over a week. They could also get water on site at a spot not too far from their camp, reducing the load of that heavy but important substance. NASA’s long-range planning, meanwhile, envisions scenarios such as a month on the moon, Hansen said. Supplies would be an interesting and heavy challenge in that situation. “The next time we’ll go back, what we’ll really be looking to do is travel much greater distances over a longer period of time,” he said. “We’ll be living in a rover for a month, covering 100 kilometers [62 miles] or more, looking for these important outcrops that tell us the story.”
Geology. The Earth is an erosive force on geology: wind, rain, glaciation, water, volcanic activity and more alters the landscape. “Sometimes the rocks look very similar” even when they are different, Hansen pointed out. Other places may have different erosion processes (think micrometeroids), making the rocks look strange to Earth-trained eyes.
Location. The landscape itself could be challenging for collecting samples. The moon, for example, has “stuff strewn everywhere and pounded into sand”, Hansen said, meaning that astronauts might have to travel much further to see something besides regolith or moon soil. Where Hansen was in the Arctic, by contrast, the group could get to more than a dozen different outcrops in a day of walking.
Gravity. The moon has a sixth of the Earth’s gravity. Mars is at about 38% Earth gravity. This means that the machines would need to be designed to work in that environment. For astronauts, it’s riskier to go up slopes or do heavy work in those conditions because their center of gravity is unfamiliar. As this Apollo 17 clip shows, astronauts sometimes fell over on the moon when doing something as simple as picking up as sample bag.
Hansen’s work in Haughton Crater did turn up some similarities to work at off-Earth locations, though. His crew had to work in a compressed time situation, learning how to find representative rocks from a 14-mile (23-kilometer) wide crater. That’s the same challenge you’d find during a moon or asteroid or Mars expedition.
“We explored not the entire crater — it’s a lot of ground to cover — but we explored some key areas,” Hansen said. “What’s important for someone like me, at my stage of geologist eyes, is to see the key aspects of the crater, those being what types of rocks that are formed and where do they end up in the crater.”
When a big rock slams into the Earth, it excavates material that is normally inaccessible to a surface visitor. Hansen was encouraged to seek the oldest or genesis rocks when on his expedition because, as in other locations, they provide clues about how the solar system was formed. The hard evidence firms up our theories on what happened.
It’s not only work in the field that is important, but work in the lab. In past years with Gordon Osinski‘s group at Western, Hansen has gone back to the university to talk with those looking at the rock samples. He asks if the samples were representative, easy to analyze. His goal is to do better with each expedition.
“It’s kind of like learning a fourth lagnguage,” said Hansen, who as a Canadian Space Agency astronaut is expected to speak English, French and Russian at a minimum.
“It’s one of those things — you can cram it all in, but you don’t retain a lot unless you use it repeatedly and continue to practice it. My elegant solution is I spend one, maybe two weeks total a year, working on this. It’s a good use of my time. I keep bringing it back, keep reviewing it and keep going a little further.”
Hansen has a busy summer ahead of him. He’s taking off soon for CF-18 training with the Royal Canadian Air Force, where he got his career start. (Funny enough, in his past career he used to survey the Arctic from the air during Canadian sovereignty operations.)
In September, Hansen is spending about a week underground in Sardinia, Italy as part of the European Space Agency’s ongoing CAVES expedition series. Besides geology, this also provides training in unfamiliar and dangerous environments.
Hansen has not been assigned to a flight yet, but continues to work in the International Space Station operations branch in Houston and to represent the Astronaut Office in operational meetings. Also in training is his colleague David Saint-Jacques. Both astronauts were selected in 2009.
The next Canadian spaceflight is expected to happen around 2018, but could be earlier depending on ongoing negotiations by the Canadian Space Agency.
“It’s like looking for a charcoal briquette in the dark,” says Bill Nye the Science Guy in this new video from AsapSCIENCE… except he’s talking about briquettes hundreds of meters wide whizzing past our planet upwards of 8, 9, 10, even 20 kilometers per second — and much, much denser than charcoal.
Near-Earth asteroids are out there (and on occasion they even come in here) and, as the planet’s only technologically advanced spacefaring species, you could say the onus is on us to prevent a major asteroid impact from occurring, if at all possible — whether to avoid damage in a populated area or the next mass extinction event. But how can we even find all these sooty space rocks and, once we do, what can be done to stop any headed our way?
Watch the video (and then when you’re done, go visit the B612 Foundation’sSentinel page to learn more about an upcoming mission to bag some of those space briquettes.)
The Earth will get another close shave Monday, when the 152 metre asteroid 2003 DZ15 makes a pass by our fair planet on the night of July 29th/30th at 3.5 million kilometres distant. This is over 9 times the Earth-Moon distance and poses no threat to our world.
This is much smaller than 2.75 kilometre 1998 QE2, which sailed by (bad pun intended) our fair world at 5.8 million kilometres distant on May 31st, 2013. The Virtual Telescope Project will be presenting a free online event to monitor the passage of NEA 2003 DZ15 starting Monday night July 29th at 22:00 UT/6:00 PM EDT.
As of this writing, no efforts are currently known of by professional observatories to monitor its passage via radar, though Arecibo may attempt to ping 2003 DZ15 on Thursday.
An Apollo asteroid, 2003 DZ15 was confirmed by the Lowell Observatory and NEAT’s Mount Palomar telescope upon discovery in February 2003. This is its closest approach to the Earth for this century, although it will make a pass nearly as close to the Earth in 2057 on February 12th.
With a perihelion (closest approach to the Sun of) 0.63 A.U.s, 2003 DZ15 can also make close passes by the planet Venus as well, which it last did in 1988 and will do again on 2056.
Closest approach of 2003 DZ15 is set for 00:37 UT July 30th, or 8:37 PM EDT the evening of Monday, July 29th. Although it will only reach about +14th magnitude (based on an absolute magnitude of +22.2), and hence be out of range to all but the very largest Earthbound backyard telescopes, it’ll be fun to watch as it slowly drifts across the starry background live on the internet. Our own, “is worth tracking down from our own backyard” limit is an asteroid passing closer than our Moon, or is farther, but is brighter than +10th magnitude… such are the limitations of humid Florida skies!
Of course, an asteroid the size of 2003 DZ15 would spell a bad day for the Earth, were it headed our way. At an estimated 152 metres in size, 2003 DZ is over seven times the size of the Chelyabinsk meteor that exploded over Russia the day after Valentine ’s on February 15th of this year. While not in the class of an Extinction Level event, 2003 DZ15 would be in 60 to 190 metre size of range of the Tunguska impactor that struck Siberia in 1908.
All enough for us to take notice as 2003 DZ15 whizzes by, at a safe distance this time. NASA plans to launch a crewed mission sometime over the next decade to study an asteroid, and perhaps retrieve a small NEA and place it in orbit about Earth’s Moon. Such efforts may go a long way in understanding and dealing with such potentially hazardous space rocks, when and if the “big one” is discovered heading our way. We’re the Earth’s first line of defense- and unlike the ill-fated dinosaurs, WE’VE got a space program and can do something about it!
Dinosaurs roamed the Earth for 135 million years. Filling every ecological niche, from the oceans, forests and plains; even the skies.
Then, 66 million years ago, something terrible happened. In a geological instant, 75% of the plants and animals on Earth went extinct. And all of the land dinosaurs were wiped off the Earth forever.
What happened? What killed them off?
What could have caused that much damage in such a short amount of time?
The key to this mystery was found in a strange layer of ash sandwiched between layers of rock deposited 66 million years ago. This line, known as the Cretaceous-Paleogene boundary, is found across the world in the geologic record and it marks the moment when everything DIED. What’s interesting about this layer is that it’s rich in iridium, a rare element on Earth, but abundant in asteroids.
And so, geologists found the most likely culprit: an asteroid.
This evidence matched the discovery of an enormous asteroid impact basin in the Yucatán Peninsula in Mexico, centered near the town of Chicxulub. The rock debris in this area could be dated back to approximately 66 million years old, matching the worldwide layer of ash.
We now know that an asteroid at least ten kilometres across slammed off the coast of Mexico 66 million years ago, releasing 2 million times more energy than the most powerful nuclear bomb ever detonated.
The effect of this impact is mindblowing.
Millions of tonnes of rock were ejected into space on ballistic trajectories. Reheated by atmospheric re-entry, this debris superheated the air across the entire planet, catching the world’s forests on fire.
Shockwaves radiated outward from the impact site, inducing earthquakes and volcanoes along their path. Mega tsunamis thousands of meters high spread out from the impact site, pounding coastlines around the world.
Dust rained down across the planet. It filled the air, darkening the skies for decades, and preventing photosynthesis. Plants on land and in the oceans were unable to produce energy.
The planet cooled from the choking dust and aerosols, followed by years of acid rain, and then even global warming as the carbon from the blasted life filled the atmosphere.
The effects to life were devastating.
It’s no surprise the land dinosaurs didn’t make it through this impact event. In fact, it’s a bigger surprise that our ancient ancestors, hardy early mammals could endure.
And our final sobering thought is that impacts of this scale have happened many times in the past, and will happen again in the future.