#NASA; #Asteroid; #NearEarthObjectStudies; #SpectrumOfLight
Washington/Canadian-Media: The largest asteroid to pass by Earth this year will approach within some 1.25 million miles (two million kilometers) of our planet on March 21, NASA said Thursday.
A NASA handout image of an asteroid. Image credit: phys.org/news
The US space agency said it will allow astronomers to get a rare close look at an asteroid.
The asteroid, 2001 FO32, is estimated to be about 3,000 feet in diameter and was discovered 20 years ago, NASA said.
"We know the orbital path of 2001 FO32 around the Sun very accurately," said Paul Chodas, director of the Center for Near Earth Object Studies. "There is no chance the asteroid will get any closer to Earth than 1.25 million miles."
That is roughly 5.25 times the distance of the Earth from the Moon but still close enough for 2001 FO32 to be classified as a "potentially hazardous asteroid."
NASA said 2001 FO32 will pass by at about 77,000 miles per hour faster than the speed at which most asteroids encounter Earth.
"Currently, little is known about this object, so the very close encounter provides an outstanding opportunity to learn a great deal about this asteroid," said Lance Benner, principal scientist at NASA's Jet Propulsion Laboratory.
NASA said astronomers hope to get a better understanding of the asteroid's size and a rough idea of its composition by studying light reflecting off its surface.
"When sunlight hits an asteroid's surface, minerals in the rock absorb some wavelengths while reflecting others," NASA said. "By studying the spectrum of light reflecting off the surface, astronomers can measure the chemical 'fingerprints' of the minerals on the surface of the asteroid."
Amateur astronomers in some parts of the globe should be able to conduct their own observations.
"The asteroid will be brightest while it moves through southern skies, Chodas said.
"Amateur astronomers in the southern hemisphere and at low northern latitudes should be able to see this asteroid using moderate size telescopes with apertures of at least eight inches in the nights leading up to closest approach, but they will probably need star charts to find it."
NASA said more than 95 percent of near-Earth asteroids the size of 2001 FO32 or larger have been catalogued and none of them has any chance of impacting our planet over the next century.
#ESA; #GeologyMysteries; #Antarctica; #AeromagneticData; #SwarmSatellite
New York/Canadian-Media: An international team of scientists has used, for the first time, magnetic data from European Space Agency (ESA)'s Swarm satellite mission together with aeromagnetic data to unravel the mysteries of the geology hidden beneath Antarctica’s kilometers-thick ice sheets, and link Antarctica better to its former neighbors, ESA news reports said.
Magnetic data how Antarctica is linked to its ancient neighbors. Image credit: ESA website.
To understand global supercontinent cycles over billions of years that have shaped Earth’s evolution, it is important to understand both Antarctic sub-ice geology and how the solid Earth itself influences the Antarctic ice sheet above it.
The research team from Germany’s Kiel University, the British Antarctic Survey and National Institute of Oceanography and Applied Geophysics, and Witwatersrand University in South Africa has today published their findings in the Nature journal Scientific Reports.
It is revealed in the study that combining satellite and aeromagnetic data provides a key missing link to connect Antarctica’s hidden geology with formerly adjacent continents, namely Australia, India and South Africa, keystones of Gondwana.
Owing to the satellites orbiting above which can see where humans cannot, makes it possible to collect both challenging and expensive geophysical information of the land below the remote Antarctica, which is covered by a massive ice sheet.
Scientists are succeeding in understanding Earth’s least accessible continent due to magnetic data from the Swarm mission along with airborne measurements in sharing a long tectonic history – and that needs piecing together like a jigsaw puzzle.
The team processed aeromagnetic data from aircraft from over southern Africa, Australia and Antarctica in a consistent manner with the help of Swarm satellite magnetic data.
Aeromagnetic data do not cover everywhere on Earth, so magnetic models complied from Swarm data help to fill the blanks, especially over India were aeromagnetic data are still not widely available. Furthermore, satellite data help to homogenise the airborne data, which were acquired over a period of more than 60 years with varying accuracy and resolution.
Jörg Ebbing, from Kiel University, explains, “With the available data, we only had pieces of the puzzle. Only when we put them together with satellite magnetic data, can we see the full picture.”
The resulting combined datasets provide a new tool for the international scientific community to study the cryptic sub-ice geology of Antarctica, including its influence on the overlying ice sheets.
Gondwana was an amalgam of continents that incorporated South America, Africa, Arabia, Madagascar, India, Australia, New Zealand and Antarctica. As the tectonic plates collided in the Precambrian and early Cambrian times some 600–500 million years ago, they built huge mountain ranges comparable to the modern Himalayas and Alps. This supercontinent started to breakup in the early Jurassic, about 180 million years ago, ultimately leaving Antarctica stranded and isolated at the South Pole, and covered in ice for around 34 million years.
“Using the new magnetic data, our animation illustrates how the tectonic plates have moved over millions of years after the breakup of Gondwana,” explains Peter Haas, PhD student at Kiel University.
Fausto Ferraccioli, Director of Geophysics at the National Institute of Oceanography and Applied Geophysics in Italy, and also affiliated with the British Antarctic Survey, said, “We have been trying to piece together the connections between Antarctica and other continents for decades. We knew that magnetic data play a pivotal role because one can peer beneath the thick Antarctic ice sheet to help extrapolate the geology exposed along the coast into the continent interior.
ESA’s Roger Haagmans, said, “This research has been carried out within ESA’s Science for Society 3D Earth study where we are using gravity data from the GOCE mission and magnetic data from the Swam mission to understand the structure and dynamic processes deep within Earth. In this instance, Swarm’s magnetic data have played a starring role.”
#Washington; #Mars2020Perseverance; #MEDA; #MOXIE
Washington/Canadian-Media: NASA’s Mars 2020 Perseverance rover performed its first drive on Mars March 4, covering 21.3 feet (6.5 meters) across the Martian landscape. The drive served as a mobility test that marks just one of many milestones as team members check out and calibrate every system, subsystem, and instrument on Perseverance. Once the rover begins pursuing its science goals, regular commutes extending 656 feet (200 meters) or more are expected.
This image was captured while NASA’s Perseverance rover drove on Mars for the first time on March 4, 2021. One of Perseverance’s Hazard Avoidance Cameras (Hazcams) captured this image as the rover completed a short traverse and turn from its landing site in Jezero Crater.
“When it comes to wheeled vehicles on other planets, there are few first-time events that measure up in significance to that of the first drive,” said Anais Zarifian, Mars 2020 Perseverance rover mobility test bed engineer at NASA’s Jet Propulsion Laboratory in Southern California. “This was our first chance to ‘kick the tires’ and take Perseverance out for a spin. The rover’s six-wheel drive responded superbly. We are now confident our drive system is good to go, capable of taking us wherever the science leads us over the next two years.”
The drive, which lasted about 33 minutes, propelled the rover forward 13 feet (4 meters), where it then turned in place 150 degrees to the left and backed up 8 feet (2.5 meters) into its new temporary parking space. To help better understand the dynamics of a retrorocket landing on the Red Planet, engineers used Perseverance’s Navigation and Hazard Avoidance Cameras to image the spot where Perseverance touched down, dispersing Martian dust with plumes from its engines.
More Than Roving
The rover’s mobility system is not the only thing getting a test drive during this period of initial checkouts. On Feb. 26 – Perseverance’s eighth Martian day, or sol, since landing – mission controllers completed a software update, replacing the computer program that helped land Perseverance with one they will rely on to investigate the planet.
More recently, the controllers checked out Perseverance’s Radar Imager for Mars’ Subsurface Experiment (RIMFAX) and Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) instruments, and deployed the Mars Environmental Dynamics Analyzer (MEDA) instrument’s two wind sensors, which extend out from the rover’s mast. Another significant milestone occurred on March 2, or sol 12, when engineers unstowed the rover’s 7-foot-long (2-meter-long) robotic arm for the first time, flexing each of its five joints over the course of two hours.
“Tuesday’s first test of the robotic arm was a big moment for us,” said Robert Hogg, Mars 2020 Perseverance rover deputy mission manager. “That’s the main tool the science team will use to do close-up examination of the geologic features of Jezero Crater, and then we’ll drill and sample the ones they find the most interesting. When we got confirmation of the robotic arm flexing its muscles, including images of it working beautifully after its long trip to Mars – well, it made my day.”
Upcoming events and evaluations include more detailed testing and calibration of science instruments, sending the rover on longer drives, and jettisoning covers that shield both the adaptive caching assembly (part of the rover’s Sample Caching System) and the Ingenuity Mars Helicopter during landing. The experimental flight test program for the Ingenuity Mars Helicopter will also take place during the rover’s commissioning.
Through it all, the rover is sending down images from the most advanced suite of cameras ever to travel to Mars. The mission’s cameras have already sent about 7,000 images. On Earth, Perseverance’s imagery flows through the powerful Deep Space Network (DSN), managed by NASA’s Space Communications and Navigation (SCaN) program. In space, several Mars orbiters play an equally important role.
“Orbiter support for downlink of data has been a real gamechanger,” said Justin Maki, chief engineer for imaging and the imaging scientist for the Mars 2020 Perseverance rover mission at JPL. “When you see a beautiful image from Jezero, consider that it took a whole team of Martians to get it to you. Every picture from Perseverance is relayed by either the European Space Agency’s Trace Gas Orbiter, or NASA’s MAVEN, Mars Odyssey, or Mars Reconnaissance Orbiter. They are important partners in our explorations and our discoveries.”
The sheer volume of imagery and data already coming down on this mission has been a welcome bounty for Matt Wallace, who recalls waiting anxiously for the first images to trickle in during NASA’s first Mars rover mission, Sojourner, which explored Mars in 1997. On March 3, Wallace became the mission’s new project manager. He replaced John McNamee, who is stepping down as he intended, after helming the project for nearly a decade.
“John has provided unwavering support to me and every member of the project for over a decade,” said Wallace. “He has left his mark on this mission and team, and it has been my privilege to not only call him boss but also my friend.”
Touchdown Site Named
With Perseverance departing from its touchdown site, mission team scientists have memorialized the spot, informally naming it for the late science fiction author Octavia E. Butler. The groundbreaking author and Pasadena, California, native was the first African American woman to win both the Hugo Award and Nebula Award, and she was the first science fiction writer honored with a MacArthur Fellowship. The location where Perseverance began its mission on Mars now bears the name “Octavia E. Butler Landing."
Official scientific names for places and objects throughout the solar system – including asteroids, comets, and locations on planets – are designated by the International Astronomical Union. Scientists working with NASA’s Mars rovers have traditionally given unofficial nicknames to various geological features, which they can use as references in scientific papers.
“Butler’s protagonists embody determination and inventiveness, making her a perfect fit for the Perseverance rover mission and its theme of overcoming challenges,” said Kathryn Stack Morgan, deputy project scientist for Perseverance. “Butler inspired and influenced the planetary science community and many beyond, including those typically under-represented in STEM fields.”
“I can think of no better person to mark this historic landing site than Octavia E. Butler, who not only grew up next door to JPL in Pasadena, but she also inspired millions with her visions of a science-based future,” said Thomas Zurbuchen, NASA associate administrator for science. “Her guiding principle, ‘When using science, do so accurately,’ is what the science team at NASA is all about. Her work continues to inspire today’s scientists and engineers across the globe – all in the name of a bolder, more equitable future for all.”
Butler, who died in 2006, authored such notable works as “Kindred,” “Bloodchild,” “Speech Sounds,” “Parable of the Sower,” “Parable of the Talents,” and the “Patternist” series. Her writing explores themes of race, gender, equality, and humanity, and her works are as relevant today as they were when originally written and published.
More About the Mission
A key objective of Perseverance’s mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the planet’s geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith.
Subsequent NASA missions, in cooperation with ESA (European Space Agency), would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis.
The Mars 2020 Perseverance mission is part of NASA’s Moon to Mars exploration approach, which includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet.
JPL, which is managed for NASA by Caltech in Pasadena, built and manages operations of the Perseverance rover.