Hubble Resumes Observing – In late October, a computer onboard the Hubble Space Telescope detected that communications between computers and instruments were missing critical synchronization messages. All instruments were placed in safe mode so ground controllers could troubleshoot the problem. They tested each instrument independently and found all operating correctly, meaning the fault was likely somewhere in the communications, though they’re still investigating the root cause. Controllers then tried operating the Hubble’s Near Infrared Camera and Multi-Object Spectrometer (NICMOS) to test communications, and were able to operate it correctly. Starting out with the NICMOS presented little risk to science as the spectrometer hadn’t been used since 2010 when a more capable instrument was installed. After that, the Advanced Camera for Surveys (ACS) was tested, and found to be communicating correctly as well. The ACS was then placed back in service and observing programs using it were resumed. On November 21, the Hubble’s most used instrument, the Wide Field Camera 3, was also brought back online. Controllers are planning new software that will work around any similar loss of messages.

Mars Helicopter – In mid-September, the Mars helicopter Ingenuity failed to lift off during a test to push the limits of its flight capabilities. Mission operators hoped that spinning its rotors faster would compensate for the thinning Martian atmosphere, a phenomenon caused by carbon dioxide seasonally freezing out into the polar caps. In a review of the test, the team determined that preflight systems had detected too much vibration and automatically canceled the flight. They corrected for the vibration and a successful flight was made on October 24, rising the planned 16 feet into the even-thinner Martian air. Ingenuity has been tested at high enough rotor spin rates that it should be able to fly throughout the season’s thinnest air.

Jupiter Discoveries – A series of new studies by an international team of researchers combined data from Jupiter probe Juno’s cloud-penetrating microwave radiometer with images of the cloud tops to better understand how the planet’s storms and cloud bands work in three dimensions. They found that cyclones are warmer at their tops, while anticyclones are cooler at their tops. Most of these rotating storms extend up to 60 miles down, much deeper than expected, while the Great Red Spot extends down 200 miles, below where the sunlight warms the atmosphere. The depth and density of the Great Red Spot is sufficient to produce a detectable gravity anomaly, something researchers will look for on future passes of the Spot. The belts and zones, respectively dark and light bands, were already known to reach depths of about 2,000 miles. The new study showed that the belts and zones have a sharp temperature change at about 40 miles deep.

Gravitational Waves – Scientists from the LIGO and VIRGO gravitational wave detectors released the results of the observation run from November 2019 to March 2020. They found 32 pairs of black holes merging and three collisions of black holes and neutron stars. Since the discovery of gravitational waves in 2015, there have now been 90 events. Most of the new events occurred billions of light-years away.

Exoplanet Atmosphere – Scientists at Arizona State University, using the Gemini South telescope in Chile, measured the amount of water and carbon monoxide in the atmosphere of an exoplanet about 340 light-years away. The planet, known as WASP-77Ab, is a hot Jupiter, a planet roughly the size of Jupiter but orbiting much closer to its star, heating the planet above 2,000 degrees Fahrenheit. The team plans to continue similar observations to measure the atmospheres of other exoplanets.

Circumbinary Planet – A team at NASA’s Goddard Spaceflight Center demonstrated a new method of detecting circumbinary planets which orbit around both stars in a stellar binary pair. The most common method of finding exoplanets is when the star dims as its planet passes in front of it, known as transiting. Distinguishing a planet from other causes of dimming requires that the period between dimmings repeats, which requires at least three transits to be observed. But for circumbinary planets, it is more complicated, because transits for each of the two stars must be distinguished from each other, as well as transits of each star by the other. In addition, the orbits of circumbinary planets tend to have longer periods because the planets orbit outside both stars. This requires observing for very long periods to catch three transit events of each star. This is further complicated as the TESS planet-finding space telescope is in an orbit that synchronizes with our Moon, so can only point in any given direction for a lunar month, not long enough to see three transits of most circumbinary planets. The team’s new technique matches just one transit of each of the pair of stars with the exoplanet’s orbit, and found the first circumbinary planet in TESS data, now designated TIC 172900988. Only a couple of dozen circumbinary planets are known.

Probable Planet in Another Galaxy – X-ray binaries can be either a black hole or a neutron star pulling in material from a companion star. In these cases, a hot accretion disk forms, emitting bright X-rays. Some of these objects have been found in nearby galaxies, not just in our Milky Way. Theoretically astronomers should be able to see the dimming from planets that orbits in front of such objects. Planets that transit in front of ordinary stars in other galaxies are too difficult to see with current technology. Transits of X-ray binaries should be easier to detect at larger distances because these X-ray source are much smaller than a star, and the planet could eclipse all the light, not just a small fraction. Now the first planet transiting an X-ray binary in another galaxy seems to have been seen by astronomers at the Center for Astrophysics, Harvard & Smithsonian. In a search of Chandra and XMM-Newton X-ray space telescope data, the apparent planet transit was found around an X-ray binary known as M51-ULS-1 in the Whirlpool galaxy. The X-rays were blocked for a few hours. Much work was done to eliminate other possible explanations for the loss of X-rays. The apparent planet would be the size of Saturn, orbiting the binary pair in about 70 years. Unfortunately this long period means that the transit cannot be checked until that 70-year period has elapsed. The hunt will continue for other planets transiting X-ray binaries.

Planet Collision – Dust and gas found around the nearby star HD 172555 about 95 light-years away, appears to be the remnants of two colliding planets. The gas is part of the atmosphere of the larger of the bodies, estimated to be about Earth-sized. This is the first detection of atmosphere that was stripped off a planet by collision. The crash probably took place at least 200,000 years ago. The star is fairly young at about 23 million years. It is thought that planet collisions are common in the early times of planet system formation. The dust is the wrong composition and grain size to be stellar formation debris, but matches that expected for collision debris. The gas was detected by astronomers at MIT using ALMA, a radiotelescope array in Chile.

Black Hole Discovered – Astronomers at Liverpool John Moores University, using the Very Large Telescope in Chile, discovered a stellar-mass black hole in a large open cluster in the Large Magellanic Cloud, a nearby galaxy. The black hole is about 11 times the mass of our Sun and was found by its gravitational influence on a star orbiting it. All other stellar-mass black holes outside our galaxy were found either because they emit X-rays from hot material falling into them, or because they give off gravitational waves when they merge with another black hole or neutron star. Most stellar-mass black holes do not emit X-rays or gravitational waves, so this discovery method may find black holes that could not otherwise be found. The newly found black hole is the first one found in a young star cluster, this one being only about 100 million years old.

MeerKAT Survey – A team of astronomers at the South African Radio Astronomy Observatory released the images from a survey of galaxy clusters made with the MeerKAT radiotelescope array in South Africa. The survey covered 115 galaxy clusters. Electrons moving near the speed of light around magnetic fields in galaxy clusters emit the radio waves that MeerKAT sees. Newly found radio emission regions in the survey should keep radio astronomers busy for years.

Warped Accretion Disk – An international team of astrophysicists found that some of the variations in brightness of a black hole known as MAXI J1820+070 are caused by a warp in the surrounding accretion disk. The black hole has a small companion star that is dumping material onto the accretion disk. As the parts of the system circle, particularly the warp in the disk, the light output varies. The system is 9,600 light-years away, one of the closest known black holes. The mass of the black hole is at least eight times that of our Sun. Much of the brightness data used was from the AAVSO, an organization that collects brightness measurements from mainly amateur astronomers.

Lunar Landing Schedule – NASA announced a new schedule for Artemis III, the mission to return people to the Moon, moving the date from 2024 to 2025. They said the previous schedule was too optimistic, that schedule had not allowed for some challenging technical developments, insufficient funds authorized by Congress, and a recently settled lawsuit. The suit, brought by Blue Origin, claimed that NASA had improperly awarded the contract to Space-X to build the lunar lander. The court decision was that the contract had been properly awarded, but settling the suit delayed progress toward Artemis III by about seven months. Artemis I will test the Moon rocket without crew, and Artemis II will fly a crew around the Moon without landing.

Space Debris – Russia conducted a test of an anti-satellite weapon on November 15 that created a cloud of space debris. NASA and others have condemned the test for the danger that the debris presents to satellites, including the International Space Station (ISS) and the Chinese space station. Astronauts aboard ISS closed hatches between modules and retreated to safe places when the debris cloud passed nearby, but fortunately no collisions resulted.