- 3463 - ASTRONOMY - Missions in 2020. Mars missions from three different countries took advantage of an alignment between Earth and the Red Planet in 2020. The missions will teach us more about Mars’ atmosphere, seek out signs of past and present life, and even cache rock samples for their future return to Earth.
------------- 3463 - ASTRONOMY - Missions in 2020.
- Astronomers saw the Milky Way doing the wave and confirmed geologic activity on Mars. The star Betelgeuse underwent a strange and striking dimming event, while naked-eye Comet NEOWISE took our breath away.
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- In May, 2020, SpaceX’s Crew Dragon capsule ferried astronauts to the International Space Station from U.S. soil, the first such trip in nearly a decade. Two months later, three new missions launched for Mars to usher in a new era of robotic exploration.
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- The global pandemic that defined much of the year changed how scientists worked and shuttered telescopes for months.
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-------------------------- Earliest galaxy group found
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- The cosmic dark ages began 380,000 years after the Big Bang. At first, no stars or galaxies existed to emit light. But even after these objects began forming, their light remained shrouded because the universe was filled with a “fog” of neutral hydrogen atoms that absorb and scatter ultraviolet light.
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- Over time, energetic ultraviolet light from early objects ionized these hydrogen atoms, knocking away their electrons. This era of reionization ended 1 billion years after the Big Bang, leaving the universe transparent to light.
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- But astronomers aren’t sure exactly what types of objects, galaxies, black holes, or stars, were responsible for clearing the fog during deionization. The Cosmic Deep And Wide Narrowband (Cosmic DAWN) survey seeking to understand this era. Astronomers also aren’t sure how fast the transition from an opaque to a transparent universe occurred.
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- Then the survey found EGS77: three galaxies shining 680 million years after the Big Bang, when the universe was just 5 percent its current age. It’s the most distant group of galaxies we have ever seen.
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- Each galaxy is generating a bubble of ionized hydrogen about 2 million to 3 million light-years across. These bubbles overlap, creating a larger, single region of space that’s free of cosmic fog, allowing light to travel freely. So far we had seen individual galaxies spread across the survey areas.
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- This is the first time we have found a group of galaxies making the universe transparent. By virtue of being in a group, EGS77’s combined bubbles allowed the team to spot fainter galaxies than could be seen if they were alone.
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- Using the same technique will allow researchers to discover more faint galaxies. That will ensure astronomers don’t underestimate the number of dim galaxies, which we know outnumber bright ones, responsible for bringing about cosmic dawn.
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------------------------------- Mars and Venus are geologically active
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- On February 24, 2020, researchers released the initial results of NASA’s InSight lander on Mars. Covering the first 10 months of the mission, the findings included the conclusion that the Red Planet is seismically active.
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- Of 174 marsquakes recorded from February to September 2019, scientists traced two of the strongest to Cerberus Fossae. This young region has undergone volcanism and other geologic changes in the last 20 million to 2.5 million years.
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- Mars’ surface is on average several billion years old, so anything in the million-year range is super intriguing. Where’s the energy for the activity coming from? Why there and not elsewhere on Mars?”
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- September 2020, InSight had recorded about 500 quakes, roughly 50 of which give clues about the planet’s deep interior. By studying how seismic waves travel through the lower crust, scientists have learned Mars’ crust is likely intact. More like Earth’s than the Moon’s, where the crust has been pummeled and fragmented by impacts.
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- But Mars isn’t the only active inner planet. There is evidence for recent volcanic activity on Venus. The circular features “ coronae“, which scientists think form when faults develop around areas where rising magma lifts up the surface.
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- By comparing 3D models of how coronae form and evolve with observations of Venus’ surface, the team concluded at least 37 of the planet’s large coronae are still evolving, indicating the planet is geologically active.
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- ----------------------------------- Betelgeuse blows in our direction?
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- Betelgeuse remains a fixture in our night sky. It’s also back to normal brightness. So, what happened? Based on Hubble Space Telescope observations leading up to the so-called “Great Dimming Event,” astronomers concluded the star “sneezed” out a cloud of hot gas from its photosphere in fall 2019.
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- By the time it reached millions of miles from the star, the cloud had cooled and condensed into dust grains that temporarily obscured the star’s southern hemisphere and made Betelgeuse appear dimmer.
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- ------------------------------ Solar science enters a golden age
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- Although the closest star to Earth has been widely studied, the Sun still maintains some secrets. The most interesting and significant solar discoveries have been coming from the Parker Solar Probe.
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- Parker, which launched in 2018 has revealed that the Sun’s magnetic field is surprisingly complex far from the star. The simple dipole (like a bar magnet) structure researchers expected is there, but overlaid with other structures as well, which scientists are now modeling to better understand.
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- Soon to observe in tandem with “Parker”is the”Solar Orbiter spacecraft“. After launching February 9, 2020, the probe made its first close pass of the Sun in mid-June. Its 10 instruments are working as expected.
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- “SoloHI” appears less affected by stray light than estimated and the magnetometer observed the signs of a coronal mass ejection event. Ultraviolet images show never-before-seen bright spots on the Sun.
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- Small and ubiquitous, each is about a millionth to a billionth the size of a traditional solar flare. Researchers have christened them “campfires,” and suspect they are either miniature solar flares or perhaps related to nanoflares, which are thought to heat the Sun’s outer atmosphere, the corona.
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------------------------------------ Crew Dragon ferries astronauts, a first:
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- Since the retirement of the Space Shuttle Program in 2011, NASA astronauts have depended on Russia for rides to the International Space Station (ISS). But that’s not the case anymore. In a historic first, the private spaceflight company SpaceX launched two American astronauts into orbit May 30 as part of the Crew Dragon Demo-2 mission.
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------------------------------------- A triple comet surprise:
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- When it was Discovered August 30, 2019, the second-known interstellar visitor to our solar system, “Comet 2I/Borisov“, hadn’t yet made its closest pass to the Sun (called perihelion). Unlike “1I/2017 U1 ‘Oumuamua“, which was spotted only after it had already rounded our star, astronomers were able to watch Borisov before, during, and after its December 8, 2019, perihelion pass.
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- On Borisov, “there was more carbon monoxide than there was water, which is much unheard of” for comets in our own solar system. That place could have been around a red dwarf star, stars smaller and cooler than our Sun, and commonplace throughout the galaxy.
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- Comet NEOWISE’s twin tails spread across the sky over West Texas. Now on its way back to the outer solar system, NEOWISE won’t return for nearly 7,000 years. It flared to naked-eye visibility between magnitude 1 and 2 after rounding the Sun on July 3, just over three months after its discovery. The comet quickly developed a picturesque pair of gas and dust tails that ultimately stretched more than 30° across the sky and offered an ideal target for astrophotographers.
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- NEOWISE spent several weeks delighting skywatchers as the brightest Northern Hemisphere comet since C/1995 O1 (Hale-Bopp). By then, the comet was a 4th-magnitude target low in the northern sky. “Over the last few weeks, NEOWISE put on a nice show for us Northern Hemisphere observers.
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------------------------------------ First midsized blackhole detected?
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- Blackholes come in a variety of sizes, ranging from a few to billions of times the mass of the Sun. Although there is ample evidence for stellar-mass and supermassive blackholes, there is surprisingly little proof of their middleweight blackholes.
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- But on May 21, 2019, scientists at the Laser Interferometer Gravitational-wave Observatory (LIGO) and the partnering Virgo site received the first convincing sign: gravitational waves that point to the violent birth of an intermediate-mass blackhole.
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- After spending more than a year scrutinizing the signal (GW190521), which lasted just a tenth of a second, on September 2, 2020, an international team of researchers released two papers detailing their results:
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- The gravitational waves originated halfway across the universe and were produced when two hefty blackholes merged to create an intermediate-mass blackhole about 142 times the mass of the Sun. Their collision also released a stupendous amount of energy, equivalent to roughly eight solar masses, as gravitational waves.
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- Although this detection confirms that intermediate-mass blackholes exist, it also raises questions. The progenitor blackholes weigh in at 66 and 85 solar masses, so the larger one firmly falls in the “pair-instability mass gap.”
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- When most massive stars die, they leave behind a blackhole. But when a star weighs 130 to 200 solar masses, photons in its core become so energetic they morph into electron-antielectron pairs, which can’t fully combat gravity. The star becomes extremely unstable and, after going supernova, leaves nothing behind.
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----------------------------------- The Milky Way does the wave.
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- Because we are embedded within the Milky Way Galaxy, mapping its large-scale structure is challenging. That is especially the case for galactic star-forming regions, huge clouds of gas and dust whose distance is difficult to measure because they aren’t points like single stars.
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- Astronomers uncovered something unexpected: the “Radcliffe Wave“. Nearly 9,000 light-years long and 400 light-years wide, this snaking line of interconnected star-forming regions rises above and dips below the plane of our galaxy. It lies less than 500 light-years from Earth at its nearest point and connects molecular clouds in Orion, Taurus, Perseus, Cepheus, and Cygnus.
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- Prior to the discovery of the Radcliffe Wave, star-forming regions were studied in relative isolation. The Radcliffe Wave showed that all these regions are connected on the grandest of scales, via tendrils of filamentary gas, which is something we never knew before.
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- This work led the effort to pin down distances to the star-forming regions that make up the Wave. That work involved combining observations of the way intervening dust and gas makes starlight appear redder with accurate distance measurements to those stars from ESA’s Gaia spacecraft.
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- Since this effect reddening is observable throughout our solar neighborhood, it allowed us to determine the distances to a huge sample of star-forming regions, using the same technique, for the first time. Previous distance techniques were piecemeal, obtained inhomogeneously on a cloud-by-cloud basis.
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------------------------------- Astronomers spy “phosphine” on Venus
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- Venus is a sizzling world thought by many to be inhospitable to life. Surface temperatures are hot enough to melt lead, almost 900 degrees Fahrenheit, while the pressure at ground level is more than 90 times that of Earth at sea level. But, life could exist in the more temperate clouds of our sister planet. And now, there could be evidence to support that hypothesis, albeit controversial evidence.
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- Researchers presented observations of an inexplicable surplus of the rancid gas phosphine in the clouds of Venus. On Earth, microbes produce most phosphine, though it can also be created abiotically under great temperatures and pressures. Measured at a level of some 20 parts per billion, the researchers say no known geological activity or exotic catalysts, such as lightning or meteorites, can explain the strength of their observed signal.
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- Many find the unexplained biosignature, or potential evidence for past or present life, tantalizing. However, others remain skeptical. Chemical compounds each have a unique spectrum, or fingerprint, that depends on the wavelengths of light they absorb.
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- If the detection holds up, “it demands follow-up”. The top three destinations to look for life in the solar system are Mars, Enceladus, and Europa, and now we should perhaps add Venus to the list. New research has come out that suggests the detected signal may have been from sulfur dioxide instead of phosphine.
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--------------------------------- Misson to Mars
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- The Red Planet has had quite a year. Not only did NASA’s InSight lander detect hundreds of marsquakes shaking the planet, but ESA’s Mars Express orbiter found more signs that the world has several underground saltwater lakes buried beneath its south pole.
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- 2020 saw three new spacecraft set forth for the Red Planet, taking advantage of a once-every-26-months alignment that shortens the time and distance required to get from Earth to Mars. As its first interplanetary mission, the United Arab Emirates launched an orbiter named al-Amal (meaning “Hope”) July 19.
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- The craft is equipped with both an infrared and ultraviolet spectrometer, meant to investigate dust, water, and ice in Mars’ lower atmosphere and to study oxygen and carbon monoxide in the upper atmosphere.
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- The craft carries a multiband camera that can achieve resolutions better than 5 miles per pixel. Altogether, Hope aims to paint a more comprehensive picture of the Red Planet’s atmosphere.
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- China launched an orbiter, lander, and rover trio to Mars July 23. Tianwen-1 (which means “heavenly questions”) is the country’s first fully homegrown Mars mission. Engineers plan for the orbiter to release the lander/rover combo after a few months orbiting the Red Planet. It will touch down near Utopia Planitia in the northern hemisphere to seek signs of past or present life.
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- Then the orbiter will enter a polar elliptical orbit around Mars. There, it will serve as a communication relay for the rover and lander, as well as use its seven science instruments to remotely study Mars’ environment and map its surface.
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- On July 30, NASA launched the Perseverance rover as part of its Mars 2020 mission. This car-sized rover, based largely on Curiosity’s design, has ambitious plans. Equipped with instruments that can create spatial maps showing the elemental and mineralogical composition of rocks, Perseverance will seek evidence that ancient life once existed in Mars’ Jezero Crater.
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- The rover also comes with a few proof-of-concept experiments: an oxygen-production device called MOXIE and a solar-powered helicopter named Ingenuity. Perseverance plans to find, collect, and seal rock and soil samples that will ultimately be returned to Earth for closer inspection with sophisticated lab equipment.
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- With all these missions expected to reach the Red Planet in February, 2021 is bound to be a big year for Mars. The missions that left Earth for Mars in 2020 — the UAE’s Hope, China’s Tianwen-1, and NASA’s Perseverance will all reach the Red Planet in February 2021.
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- NASA’s Double Asteroid Redirection Test, or DART mission, will launch July 22, 2021, to binary asteroids Didymos and Dimorphos. The agency’s Lucy spacecraft is scheduled to launch October 16, 2021,the first mission to Jupiter’s Trojan asteroids.
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- The Indian Space Research Organisation’s Chandrayaan-3 mission, which comprises a lander and rover, is scheduled to launch for the Moon in late 2021.
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- The ESA and Roscosmos’ robotic Luna-25 lander aims to put Russia back on the Moon with an anticipated launch date in October 2021.
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- First light for the 8.4-meter Simonyi Survey Telescope at the Vera C. Rubin Observatory in Chile is expected in October 2021.
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- Both the Parker Solar Probe and Solar Orbiter will make flybys of Venus in 2021: Parker will make two, Solar Orbiter will make one.
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- The uncrewed Artemis I mission, the first in NASA's plan to return humans to the Moon, is scheduled to launch in 2021. This first mission will combine the new Space Launch System rocket and Orion crew capsule.
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February 17, 2022 ASTRONOMY - Missions in 2020 3464
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----------------------------- Thursday, February 17, 2022 ---------------------------
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