This week at NASA:
🚀 Preparing to #LaunchAmerica 🛰️ JAXA’s spacecraft delivers cargo to the International Space Station 🕵️♂️ The detective capabilities of NASA’s Perseverance Mars Rover.
Category: space – Page 680
Jupiter has captured an icy comet from the outer solar system in a bizarre orbit that will bring it back to within 3 million kilometers of the giant planet in 2063. The only Sun-orbiting objects known to come closer were the fragments of Comet Shoemaker-Levy 9, which plunged into the Jovian cloud deck in July 1994.
A year ago, NASA’s asteroid-hunting ATLAS project in Hawai’i discovered 2019 LD2, and further observations showed it was a comet. New observations this spring confirmed it as a periodic comet and placed its orbit near Jupiter, leading Larry Denneau (University of Hawaii) to announce May 20th that P/2019 LD2 was the first comet among the Trojans. This family of several thousand asteroids shares Jupiter’s orbit but stays steady at about 60° ahead or behind of the planet. The discovery of a comet among Trojan asteroids was surprising because most of them are thought to have been captured in the solar system’s early years — any ices ought to have evaporated long ago.
However, when amateur astronomer Sam Deen used software on the Jet Propulsion Laboratory’s solar-system dynamics website to calculate the object’s orbit, he found P/2019 LD2 recently had a close encounter with Jupiter that left its orbit unstable. The model showed that the comet had likely been a Centaur, part of a family of outer solar system asteroids, with an orbit reaching out to Saturn. Then, on February 17, 2017, it passed about 14 million kilometers from Jupiter, an encounter that sent the comet on a wild ride and inserted it into an odd Jupiter-like orbit.
Anyons – the particle-like collective excitations that can exist in some 2D materials – tend to bunch together in a two-dimensional conductor. This behaviour, which has now been observed by physicists at the Laboratory of Physics of the ENS (LPENS) and the Center for Nanoscience and Nanotechnologies (C2N) in Paris, France, is completely different to that of electrons, and experimental evidence for it is important both for fundamental physics and for the potential future development of devices based on these exotic quasiparticles.
The everyday three-dimensional world contains two types of elementary particles: fermions and bosons. Fermions, such as electrons, obey the Pauli exclusion principle, meaning that no two fermions can ever occupy the same quantum state. This tendency to flee from each other is at the heart of a wide range of phenomena, including the electronic structure of atoms, the stability of neutron stars and the difference between metals (which conduct electric current) and insulators (which don’t). Bosons such as photons, on the other hand, tend to bunch together – a gregarious behaviour that gives rise to superfluid and superconducting behaviours when many bosons exist in the same quantum state.
Within the framework of quantum mechanics, fermions also differ from bosons in that they have antisymmetric wavefunctions – meaning that a minus sign (that is, a phase φ equal to π) is introduced whenever two fermions are exchanged. Bosons, in contrast, have symmetric wavefunctions that remain the same when two bosons are exchanged (φ=0).
In the local (redshift z ≈ 0) Universe, collisional ring galaxies make up only ~0.01% of galaxies1 and are formed by head-on galactic collisions that trigger radially propagating density waves2,3,4. These striking systems provide key snapshots for dissecting galactic disks and are studied extensively in the local Universe5,6,7,8,9. However, not much is known about distant (z 0.1) collisional rings10,11,12,13,14. Here we present a detailed study of a ring galaxy at a look-back time of 10.8 Gyr (z = 2.19). Compared with our Milky Way, this galaxy has a similar stellar mass, but has a stellar half-light radius that is 1.5–2.2 times larger and is forming stars 50 times faster. The extended, diffuse stellar light outside the star-forming ring, combined with a radial velocity on the ring and an intruder galaxy nearby, provides evidence for this galaxy hosting a collisional ring. If the ring is secularly evolved15,16, the implied large bar in a giant disk would be inconsistent with the current understanding of the earliest formation of barred spirals17,18,19,20,21. Contrary to previous predictions10,11,12, this work suggests that massive collisional rings were as rare 11 Gyr ago as they are today. Our discovery offers a unique pathway for studying density waves in young galaxies, as well as constraining the cosmic evolution of spiral disks and galaxy groups.
Circa 2017
Japanese scientists are developing a system to capture and remove space debris.
The existence of a planet the size of Earth around the closest star to the Sun, Proxima Centauri, has been confirmed by an international team of scientists including researchers from the University of Geneva (UNIGE). The results, published in Astronomy & Astrophysics, reveal that the planet in question, Proxima b, has a mass of 1.17 Earth masses and is located in the habitable zone of its star, which it orbits in 11.2 days.
This breakthrough was possible thanks to radial velocity measurements of unprecedented precision using ESPRESSO, the Swiss-manufactured spectrograph, the most accurate currently in operation, which is installed on the Very Large Telescope in Chile. Proxima b was first detected four years ago by means of an older spectrograph, HARPS, also developed by the Geneva-based team, which measured a low disturbance in the star’s speed, suggesting the presence of a companion.
The ESPRESSO spectrograph has performed radial velocity measurements on the star Proxima Centauri, which is only 4.2 light-years from the sun, with an accuracy of 30 centimetres a second (cm/s), about three times more precision than that obtained with HARPS, the same type of instrument but from the previous generation.
Are you up for the challenge?
Venus is an EXTREME world, and we’re calling on YOU to help us explore it! NASA Jet Propulsion Laboratory is running a public challenge to develop an obstacle avoidance sensor for a possible future Venus rover: https://go.nasa.gov/36Cj5QE
🏆 1st place prize: $15,000.
China’s space program will launch a Mars mission in July, according to its current plans. This will include deploying an orbital probe to study the red planet, and a robotic, remotely-controlled rover for surface exploration. The U.S. has also been planning another robotic rover mission for Mars, and it’s set to take off this summer, too – peak time for an optimal transit from Earth to Mars thanks to their relative orbits around the Sun.
This will be the first rover mission to Mars for China’s space program, and is one of the many ways that it’s aiming to better compete with NASA’s space exploration efforts. NASA has flown four previous Mars rover missions, and its fifth, with an updated rover called ‘Perseverance,’ is set to take place this years with a goal of making a rendezvous with Mars sometime in February 2021.
NASA’s mission also includes an ambitious rock sample return plan, which will include the first powered spacecraft launch from the red planet to bring that back. The U.S. space agency is also sending the first atmospheric aerial vehicle to Mars on this mission, a helicopter drone that will be used for short flights to collect additional data from above the planet’s surface.
The US Space Force has announced that it is looking for a place to establish its new HQ, and is encouraging communities across the US to nominate themselves based on a set of criteria.