SLS Launch Further Delayed – Following previous technical delays, the first Space Launch System (SLS) rocket returned to the safety of NASA’s Vehicle Assembly Building before the landfall of Hurricane Ian. After confirming that it suffered no damage, NASA announced they’re likely to make another launch attempt in November. Hydrogen leaks, a temperature sensor problem, weather and other issues had previously delayed as well. When it does launch, the uncrewed Artemis 1 mission will test the SLS rocket and the Orion capsule’s ability to orbit the Moon and return to Earth. Artemis 2, with crew aboard, is still scheduled to orbit the Moon in 2024. The SLS rocket has more liftoff thrust and more payload-to-orbit than the Saturn V rockets used for the Apollo missions to the Moon. Though the Soviet N1 rocket, designed to take cosmonauts to the Moon, had more liftoff thrust than SLS, by other measures, SLS will be the most powerful rocket ever (the N1 never successfully orbited in four attempts).
Stars Flaring – The TESS space telescope searches for planets by looking for them as they pass in front of their stars, but in doing so, it also recorded more than 25,000 stars flaring. A computer program by astronomers at the University of Wroclaw sorted these flarings out from other blips in stars’ light. Of the observed stars, 7.7 percent of them flared. The flares were similar to those observed on our own Sun, but some were much stronger, up to a billion times the energy of a typical flare on the Sun. Most of the stars found to flare had temperatures lower than 8,000 degrees Kelvin. Red dwarfs were more likely to flare than other types of stars.
Cosmic Ray Source – Cosmic rays are subatomic particles, mostly protons, traveling through the universe at near the speed of light. Many cosmic rays are more energetic than can be achieved by the most powerful particle accelerators on Earth. Because cosmic rays are deflected by magnetic fields, it has been extremely difficult to trace them back to their source and pin down where they originate. However, if they originate in an area with substantial interstellar gas, then cosmic rays colliding with the gas create gamma rays, which are not deflected by magnetic fields and point directly back to their source. A new study by scientists at the University of Wisconsin Madison, using 12 years of data from the Fermi Gamma-ray Space Telescope, found such a gamma-ray source that is also a cosmic-ray source, the supernova remnant known as G106.3+2.7. The shock wave from the exploding supernova is accelerating protons to extremely high energies to become cosmic rays. More work is needed to show if all supernova remnants can produce cosmic rays, and if supernova remnants are the only source of cosmic rays.
Gravity Is Unchanging – A new study by scientists at NASA’s Jet Propulsion Laboratory, using data from the Dark Energy Camera on the Victor M. Blanco 4-meter telescope in Chile and other telescopes, found that the strength of gravity has not changed measurably for the past five billion years. Einstein’s theory of general relativity assumes gravitational strength remains constant, but some other competing theories call for it to change with time. The team calculated the strength of gravity by measuring the amount that light from distant objects was bent as it passed by a massive object. The Euclid and Nancy Grace Roman space telescopes, to launch in the next few years, will be able to make similar measurements to greater distances, and therefore further back in time.
Star Formation in the Galactic Center – A new high-resolution infrared survey by the Max Planck Institute for Astronomy of the center of our Milky Way galaxy has given astronomers the best data yet on star formation in the region. Visible light from the center is blocked by dust, but some infrared wavelengths penetrate through. The researchers found in the central region, which stretches about 1,300 light-years across, that the star formation rate has been about ten times higher than the galactic average over the past 100 million years. The star formation started out near the center and worked outward, which matches star formation patterns seen in other galaxies. The team also found that most stars in the Milky Way central region formed in loose associations rather than tight clusters and the member stars of these associations have dispersed since their formation. The variety of star ages found showed that star formation occurred in various phases that took place as much as seven billion years ago. The new survey was made with infrared instruments on the Very Large Telescope in Chile and obtained data on three million stars near the galactic center. Even with three million stars, the survey was seeing only the brighter stars due to the distance of the galaxy center. Astronomers plan to follow up this survey with observations of spectra and proper motions of these same stars.
Star Formation Stops – Galaxy SDSS J1448+1010 recently stopped forming stars. Observations by astronomers at Texas A&M University, made using the ALMA radiotelescope array in Chile and the Hubble Space Telescope, found that a collision with another galaxy flung away much of the cool gas that form stars. This is surprising because most other galactic collisions prompted more star formation, not less. There is evidence that the galaxy underwent a burst of star formation just before it quit about 70 million years ago. Many astronomers have long believed that a rash of supernovas would blow away or heat the cold gas of a galaxy and stop star formation, so there may be more than one way to stop.
SMC Star Formation – A team of astronomers at Osaka Metropolitan University observed massive young stars in the Small Magellanic Cloud (SMC) using the ALMA radiotelescope array. The SMC has a low amount of elements heavier than helium, and star formation there should resemble the early Universe, before heavier elements had formed in high abundances. The observations showed high-speed double gas streams flowing out of a forming star known as Y246. Such streams are known to occur in star formation where there are abundant heavy elements, but this shows the same process occurs in low abundance formations. Such streams are believed to discard excess spin in the collapsing gas clouds to aid in star formation.
Oldest Planetary Nebula – A team of astronomers at the University of Hong Kong discovered the oldest known planetary nebula. A planetary nebula forms when a star near the end of its life blows off material in an expanding cloud, which usually dissipates in 10 or 20 thousand years. The speed of expansion of the new discovery indicates it is about 70,000 years old. Despite them having nothing to do with planets, astronomer William Herschel dubbed these gas clouds “planetary” only because the round ones resemble planets through a small telescope. The new discovery is located in the open star cluster M37. There are only three planetary nebulas known to be members of open clusters. The researchers believe that there is less disruption from interstellar medium within an open cluster, which allows a planetary nebula there to resist dissipation longer.
Exoplanet Atmospheric Carbon Dioxide – A research team led by scientists at the University of California at Santa Cruz using the James Webb Space Telescope (JWST) made the first ever certain detection of carbon dioxide in the atmosphere of an exoplanet. As WASP-39b passed in front of its star the telescope observed the planet’s spectrum. It is a gas giant planet with roughly a quarter the mass of Jupiter, located about 700 light-years away. It orbits its Sun-like star quite closely, so is puffed up from the heat. The planet was discovered in 2011 by its dimming of its star when it transited in front. Previous observations by other telescopes had detected water vapor, sodium and potassium in the planet’s atmosphere, but it took the Webb scope to detect the weaker signal of carbon dioxide.
Exoplanet Imaged – The James Webb Space Telescope (JWST) imaged its first exoplanet, though it already observed other exoplanets too close to their stars to be separately resolved. The planet is known as HIP 65426 b, is a gas giant nine times the mass of Jupiter, and about 355 light-years away. It had previously been imaged in infrared by the Very Large Telescope in Chile. Because JWST can operate at much longer infrared wavelengths than Earth-based telescopes, the new images should reveal more about the planet. The new images were made using a coronagraph on JWST to block the blindingly brighter light of the planet’s star. The planet orbits quite far from its star, taking 630.7 Earth years to complete one orbit, but this great distance makes it easier to image.
Binary Star and Planet Orbits – Astronomers at the National Autonomous University of Mexico mapped in three dimensions the orbits of a binary star and the planet that orbits one of them. The team used the Very Long Baseline Array (VLBA), a network of ten radiotelescopes across the country, to observe the star pair known as GJ 896 located about 20 light-years away. Both are red dwarf stars, considerably smaller than our Sun. Their orbit about each other is about the size of Neptune’s orbit about the Sun. The planet is about twice as massive as Jupiter and its year is 284 Earth days. The planet orbits in the opposite direction that the stars orbit each other, and the planes of planet orbit and star orbit are tilted by 32 degrees. Astronomers had thought that planets and companion stars would form from the same disk, and therefore orbit eachother in the same plane and direction. Astronomers are also having trouble explaining how such a large planet would form about such a small star.
Water World – A team of astronomers at the University of Montreal discovered an exoplanet that has a substantial content of water, far more than Earth’s oceans. The planet is known as TOI-1452 b, and found orbiting a star in a binary system about 100 light-years away in Draco. The planet’s diameter and mass are somewhat larger than Earth’s, and it orbits in the habitable zone, the area where temperatures should allow liquid water to exist on its surface. It was first detected by the TESS planet-finding space telescope, and was then observed by ground-based telescopes. These determined the planet’s mass, which showed its density is too low to be an entirely rocky planet, and must be made up of as much as 30 percent water. The host star is smaller and dimmer than our Sun, and the planet’s year is only eleven Earth days. The astronomers hope to further study this planet with the Webb Space Telescope.
Nearby Black Hole – Researchers at the Center for Astrophysics | Harvard & Smithsonian examined data from the Gaia Space Telescope and found a Sun-like star about 1,500 light-years away is orbiting an object about ten times the mass of our Sun, that is so dark it must be a black hole. The Sun-like star is a G type star with heavy element content about that of the Sun. It revolves about the dark object every 185.6 Earth days in a modestly eccentric orbit. The dark object would be the nearest known black hole. But the difficulty of finding it implies there may be many more nearby black holes waiting to be discovered.
Missing Carbon Monoxide – It has long been a mystery why the concentration of carbon monoxide observed in planet-forming protoplanetary disks is often less than in computer simulations. A new model by scientists at the Center for Astrophysics | Harvard & Smithsonian better matches observations, showing the carbon monoxide is freezing into a solid that’s much more difficult to detect. The simulation was validated by matching it with observations of four protoplanetary disks using Chile’s ALMA radiotelescope array. The freezing starts about a million years into the planet forming process. Because carbon monoxide gas is easy to detect, it is often used to estimate other constituents, so getting the carbon monoxide concentration right is important to understanding planet formation.
Solar Switchbacks – Solar space telescopes, including the Parker Solar Probe, have occasionally flown through sharp reversals of the Sun’s magnetic field, dubbed switchbacks. For the first time a spacecraft, the Solar Orbiter spacecraft, has imaged a whole S-shaped magnetic feature that must be such a switchback. It was located above an active sunspot region, which apparently was the source of the feature. The circumstances recorded by the orbiter match one theory of how switchbacks form. Open magnetic fields stretching away from the Sun interact and reconnect with closed magnetic fields that loop back into the Sun, creating a new open magnetic field line with S-shaped kinks in it. The kinks then rise away from the Sun. It has been observed that solar wind speeds up in a switchback, so this may explain the mystery of how solar wind gets hotter and faster as it recedes from the Sun.
Mars Rover Radar – Analysis by researchers at the University of California, Los Angeles of ground-penetrating radar observations from the Mars rover Perseverance showed the geology of Jezero Crater is more complicated than expected, with tilted rock layers rather than horizontal layers of lava or sediment deposited over time. Most of the rocks found in the bottom of the crater are volcanic rock. The non-volcanic rocks seem to be limited to the delta area where water flowed into Jezero billions of years ago. The rover continues to sample rocks and soil, some of which will be brought back to Earth on a future mission. The radar observations give context to these samples.
Mars Water Lacking – Scientists at the the University of California San Diego released a new analysis of seismic data from the Insight Mars lander. The top 1,000 feet beneath the lander contains little ice. The crust is more porous than expected. Sediments are not well cemented. Scientists expected the water that was once plentiful billions of years ago to be found underground in minerals that cemented sediments together or as underground ice. Other missions have found plentiful underground ice, but closer to the planet’s poles.
Green Planet? – Mars is known as the Red Planet because almost all its surface is covered with rusty red dust. But scientists at Purdue University analyzing data from the rover Perseverance, also found large grains of the green mineral olivine. The rocks including the olivine are believed to be volcanic in origin with some interaction with water, and are probably close to four billion years old.
Frank Drake, key figure in the search for extraterrestrial intelligence (SETI), died at age 92. About 60 years ago he planned and executed Project Ozma, which listened (unsuccessfully) for signals from nearby stars Tau Ceti and Epsilon Eridani by radiotelescope. Decades later astronomical observations found planets orbiting those stars. Drake developed the Drake Equation, which figured the probable number of civilizations in our galaxy that might communicate with us. At the time, most of the factors in the Equation were unknown, but astronomers now have a good idea of such factors as the fraction of stars that have planets. Other factors, like the fraction of planets that develop intelligent life, are still anybody’s guess. But the Equation began the discussion on SETI. Drake has said that his best accomplishment was the nine years he spent answering calls on the Suicide Prevention Hotline.
Pre-Solar Material – Scientists at the Carnegie Institution for Science, analyzing samples returned from asteroid Ryugu by the Hayabusa2 spacecraft, found microscopic grains older than our Sun. The ages were found by the ratios of isotopes of elements. Similar pre-solar grains have been found in carbonaceous chondrites, a type of meteorite. Most newly recovered grains were similar to other types of meteorite grains, but included a new silicate. This reinforces the theory that microscopic grains get recycled from earlier stellar systems to later ones.
Voyager 1 Repaired – For several months, the Voyager 1 spacecraft was jumbling some of the data it sent to Earth. Mission control found the spacecraft was sending attitude data through a faulty onboard computer that had been turned off years ago. Controllers again commanded Voyager to turn off the faulty computer and use its backup computer, correcting the problem. Voyager 1 continues to collect data on interstellar space about 45 years after it was launched to Jupiter and Saturn.
Rocket Failure – A Blue Origin New Shepard rocket failed about a minute into flight. The capsule contained only zero-gravity science experiments, no crew. The escape system worked perfectly and separated the capsule from the rocket, gently returning it to Earth by parachutes. The same rocket system has launched several crews into near space successfully.
Starliner Delayed – Boeing announced that its Starliner space capsule will undergo some fixes that will delay its first launch with crew until next February. The Starliner is the second privately developed crew space capsule, after SpaceX’s Crew Dragon. Starliner had two thrusters fail during its last test flight without crew to the International Space Station. The thrusters are on a part of the spacecraft that is burned up on return to Earth, so it may take awhile to determine the necessary fixes.
