Blog about ESA activities.
A few hours ago, the Sentinel-6B satellite was launched atop a Falcon 9 rocket from the Vandenberg base. After about 57 minutes, it successfully separated from the rocket’s last stage and set off on its course to reach the polar orbit at 1,336 kilometers altitude where its scientific mission will begin, taking over from the Sentinel-6A Michael Freilich satellite, which was launched on November 21, 2020.
A few hours ago, the Sentinel-1D satellite, part of the Copernicus / GMES, was launched from the Kourou spaceport, in French Guiana, atop an Ariane 6 rocket. After about 34 minutes, the satellite regularly separated from the rocket’s last stage and started sending signals. Its final orbit in low Earth orbit will be at an altitude of about 693 kilometers.
An article published in the journal “Astronomy and Astrophysics” reports the results of a study that provides evidence that a sort of giant cosmic wave is crossing the Milky Way, propagating from the center outward from the galactic disk, causing a corrugation. A team of researchers led by Eloisa Poggio of the Italian National Institute for Astrophysics used data collected by ESA’s Gaia space probe to map the motions of thousands of young giant stars and Cepheids within the corrugation, reconstructing the wave that generates them. The cause may be the aftermath of an ancient collision with a dwarf galaxy, but follow-up studies are needed to assess this and other possible explanations.
A little while ago, SpaceX’s Crew Dragon Grace spacecraft concluded its Ax-4 mission by splashing down without problems. On board were Shubhanshu Shukla, Peggy Whitson, Sławosz Uznański-Wiśniewski, and Tibor Kapu, who ended this completely private space mission in the Atlantic Ocean after leaving the International Space Station almost 48 hours earlier. Shortly after splashing down, SpaceX’s recovery ship went to retrieve the Grace and its crew to transport them to the coast.
ESA has published a photo of the Arcadia Planitia region on Mars captured by its Mars Express space probe’s High Resolution Stereo Camera (HRSC). This is an interesting region from a geological point of view because it’s northwest of the large volcanoes of Tharsis, the largest in the entire solar system, and traces of ancient lava flows are still visible. It could be important for the exploration of the red planet if confirmation of the presence of frozen water right under the surface were to arrive.
