. | . |
Solar Orbiter returns to Earth before starting its main science mission by Staff Writers Paris (ESA) Nov 19, 2021
Solar Orbiter is returning to Earth for a flyby before starting its main science mission to explore the Sun and its connection to 'space weather'. During the flyby Solar Orbiter must pass through the clouds of space debris that surround our planet, making this manoeuvre the riskiest flyby yet for a science mission. Solar Orbiter's Earth flyby takes place on 27 November. At 04:30 GMT (05:30 CET) on that day, the spacecraft will be at its closest approach, just 460 km above North Africa and the Canary Islands. This is almost as close as the orbit of the International Space Station. The manoeuvre is essential to decrease the energy of the spacecraft and line it up for its next close pass of the Sun but it comes with a risk. The spacecraft must pass through two orbital regions, each of which is populated with space debris. The first is the geostationary ring of satellites at 36 000 km, and the second is the collection of low Earth orbits at around 400 km. As a result, there is a small risk of a collision. Solar Orbiter's operations team are monitoring the situation very closely and will alter the spacecraft's trajectory if it appears to be in any danger.
Earth science opportunity The details of these interactions are being studied by two ESA missions: Cluster's four satellites at 60 000 km in altitude and Swarm's three spacecraft at 400 km. Multiple spacecraft are needed to break the so-called space-time ambiguity. This is the name given to the uncertainty over whether a change has taken place because a spacecraft has flown into a different region with different conditions (a change in space) or is flying through a region that changes its conditions (a change in time). Solar Orbiter's flyby offers a unique opportunity to take even more data. It will sweep into the Earth's magnetic field from out beyond Clusters orbit, approach Swarm's orbit at closest approach and then fly back out again. This will provide even more data points from which to reconstruct the condition and behaviour of Earth's magnetic field during the flyby. "This flyby is exciting: seeing what Solar Orbiter sees in our part of space, and how that compares to what we are seeing, and if there are surprises, what are they?" says Anja Stromme, Swarm Mission Manager.
Cruise phase complete Despite Solar Orbiter not yet being in full science mode, a lot of science has been produced. "Scientifically, this exceeded our expectations by a large margin," says Daniel Muller, Solar Orbiter Project Scientist. He explains that an upgrade to the ESA Ground Station Network allowed Solar Orbiter to send more data than expected back to Earth, and the mission's scientists have been quick to take advantage. More than fifty papers detailing Solar Orbiter's cruise phase science results are to be published in December by the journal Astronomy and Astrophysics.
Closer to the Sun "This will be at a third of the distance between the Sun and Earth. So compared to all the interesting high resolution images that we've already gotten everything now will be zoomed in by about a factor of two," says Daniel. This includes new views of the enigmatic 'campfires' that Solar Orbiter saw at the first perihelion. The campfires could hold clues about how the Sun's outer atmosphere has a temperature of millions of degrees, while the surface has a temperature of thousands - which seemingly defies physics because heat should not be able to flow from a colder to a hotter object. And while Solar Orbiter is not going as close to the Sun as NASA's Parker Solar Probe, this is by design because it allows Solar Orbiter to not only measure what is happening in the solar wind, but to also carry telescopes that can look at the Sun without being destroyed by the heat. The two data sets can then be compared to link activity on the Sun's surface to the space weather around the spacecraft. "This linkage science is what I find most exciting," says Yannis Zouganelis, Solar Orbiter Deputy Project Scientist.
Observing challenge In the moments leading up to closest approach, skywatchers in the Canaries and North Africa could catch a brief glimpse of the spacecraft speeding through the sky. It will be travelling at about 0.3 degrees per second, which is just over half the apparent diameter of the Moon every second. For most observers it will be too faint to spot with the unaided eye, and too fast for telescopes to track, so binoculars should provide the best chance of catching a glimpse. When Solar Orbiter re-emerges from the Earth's shadow it will be on course for its rendezvous with the Sun and the never-before-seen solar polar regions. The science phase of this ambition mission will have begun.
Space dust presents opportunities, challenges as Parker Solar Probe speeds towards Sun Washington DC (SPX) Nov 18, 2021 Propelled by a recent swing past Venus, NASA's Parker Solar Probe is healthy and performing normally as it heads toward its next closest approach to the Sun on Nov. 21. Parker Solar Probe will break its own distance and speed records on that approach - the 10th of 24 planned, progressively closer trips around the Sun - when it comes about 5.3 million miles (8.5 million kilometers) from the Sun's surface, while reaching top speeds of 101 miles (163 kilometers) per second, or 364,621 miles per hour. ... read more
|
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |