ASTRONOMY

In the Sky this Week, Astronomy News, and TWSftUoTtCBDftSoTiFoOT

ASTRONOMY NEWS

Interstellar Interlopers: Astronomers’ ability to identify, and calculate trajectories for, small objects approaching Earth has grown greatly of late. Most of the objects found have highly-elliptical orbits around the Sun, members even if distant of the outermost Solar System. However, two objects recently came through that were not gravitationally bound to the Sun, Oumuamua and Borisov. Astronomers rushed to study these interstellar ambassadors, but responding to sightings quickly enough is a problem. The potential scientific value of truly interstellar material is large, and NASA and ESA are both developing mission concepts that would all robotic sampling of the next interstellar object to pass by, Bridge (NASA) and Comet Interceptor (ESA). RAMA, look out! For a summary of this aspect of planetary protection, see: https://phys.org/news/2025-04-mysterious-stars-solar-scientists.html; for Bridge, see: https://www.sciencedirect.com/science/article/abs/pii/S0032063320303500; and for Comet Interceptor, see: https://link.springer.com/article/10.1007/s11214-023-01035-0.

Nearby Supernova: Astronomers at the University of Warwick have found a compact binary star system only ~150 light-years away that will likely produce a powerful Type 1s super-nova explosion. But not to worry, the event lies some 23 billion years in the future. The two stars in the system are larger white dwarf stars, orbiting one another separated by only a few million miles. That’s close enough for mass to be ripped from one and passed to the other, a process that will eventually cause the two to merge. Most Type 1a supernovae are formed by collisions between two white dwarfs or a white dwarf and a neutron star. If the Earth is still 150 light-years away when that collision happens, the resulting supernova will be on the order of ten times brighter than the full Moon. For more on this discovery, see: https://www.sciencedaily.com/releases/2025/04/250404122624.htm.

Supernovae Were Bad News for Paleozoic Life: Geologists use abrupt changes in fossil assemblages to denote boundaries of geologic time periods. Perhaps the best known is the Chicxulub impact event that “killed off the dinosaurs,” marking the end of the Mesozoic Era. But not all mass extinction events are due to asteroid impacts. Recent research conducted at Keele University suggest that nearby supernovae explosions were responsible for mass extinction events in the Paleozoic Era. The earliest came in the Ordovician Period, 445 million years ago, and was marked by the extinction of 60% of the marine invertebrates alive at that time (there were few land-dwellers that long ago). The second came in the late Devonian Period, 372 million years ago, which wiped out 70% of all species then living, and made abrupt changes in marine animals of that time. The mass extinctions had been known about for some time, but there was no meteoritic material in deposits of that time, like there was at Chicxulub. The timing and frequency of supernova events in the Milky Way is consistent with the timing of the extinction events, which would have been capable of depleting Earth’s ozone layer in the upper atmosphere, allowing killing radiation to play havoc with the species living at that time. For more info on this story, see: https://www.sciencedaily.com/releases/2025/04/250404122624.htm.

Supernovae, Impacts, and Humans: The two previous stories are built around mass extinctions in the geologic record. Five major ones are known, including the three mentioned above. There is strong evidence that we are presently living in the sixth, this time caused by human activity. Research evidence indicates that 7.5 – 13% of the species present in 1500 CE have become extinct, most due to habitat loss and climate change induced by human activity. 500+ years is a long time by human standards, but a mere eyeblink in terms of geologic time, so the observed reduction in species could be construed as a “mass extinction” event. Read more about this issue while you still can at: https://www.sciencedaily.com/releases/2022/01/220113194911.htm.

Black Holes: Beginnings?! When the expansion of the Universe became general consensus, several aspects of it were troubling from a philosophical point of view. Questions like: “What happened before the Big Bang?” and “What happens in the future when matter is spread out to the extreme?” were the subject of speculation. One idea was the Steady-State Hypothesis, which held that matter was being continuously created to maintain the Universe’s overall density. But that required an almost magical creation of something from nothing. Another was the “Oscillating Theory,” which held that the present observed expansion would be eventually countered by gravity, causing the expansion to cease, then contraction until all matter was concentrated in one mass, aka the “Big Crunch.” Rinse and repeat, the cycles of creation/destruction have existed and will always exist. But the observed rate of expansion is presently increasing, not decreasing….

How’s this for a teaser to a news article?

“New research suggests black holes may transition into 'white holes', ejecting matter and potentially even time back into the universe, defying our current understanding of these cosmic giants. The study by the University of Sheffield proposes a revolutionary link between time and dark energy, suggesting that the mysterious force driving the universe's expansion may be used to measure time.”

Find out more about this astonishing idea here: https://www.sciencedaily.com/releases/2025/03/250312124602.htm.

Primordial Galaxy’s Complex Chemistry: The JWST was created to examine the most distant objects, from which light has been travelling for most of the Universe’s history. One activity getting adequate observing time is the JWST Advanced Deep Extragalactic Survey. The team working up the survey had already found the most distant galaxy to date, designated JADES-GS-z14-0. Further examination of this particular galaxy, as seen when the Universe was only 300 million years old, was startling. Most ideas of the early Universe had hydrogen, helium, and maybe tiny amounts of lithium as its only matter. But the spectrum of the newly-discovered galaxy showed a lot of oxygen, an element that would have to have been made within a star, then released upon that star’s “death.” Going from Big Bang to star formation, evolution, and death, then to incorporation into a second-generation set of stars in the observed galaxy in only 300 million years is difficult to understand. Find out more about this discovery at: https://www.sciencedaily.com/releases/2025/03/250310152925.htm.

Proxima Centauri Gets the Fame, But….  It’s behind in the exoplanet race. Famed because it is the closest star to Earth (barely), even though it is much dimmer than the star it orbits, Alpha Centauri. The star that is #2 on the “Closest” list to the Alpha Centauri system is much less well-known, Barnard’s Star. It’s a red dwarf star, with only 16% of the mass of our Sun, discovered in the constellation of Ophiuchus in 1916 by astronomer E.E. Barnard. Its identity was revealed by its large “proper motion,” being close enough for its relative motion to be seen to across the pattern of background stars by comparing images taken but a few years apart. It’s a “mere” 6 light-years away, making it the focus of a search for exoplanets for decades, that had until now been difficult. Recent detailed observations have shown Barnard’s Star to have four small planets, topping Proxima by one (see below). All four lie inside the “Goldilocks Zone” and are likely unsuitable for life. Their orbits lie very close to each other, suggesting they are very circular or very young. For more info, see: https://skyandtelescope.org/astronomy-news/confirmed-at-last-barnards-star-hosts-four-tiny-planets.

Proxima’s New Planet: Proxima Centauri, the star closest to the Solar System, was already known to have two planets in orbit around it. Astronomers just discovered a third. It’s one of the smallest exoplanets detected to date, only having a quarter of Earth’s mass, and orbits Proxima at a distance of only four million miles, inside of the “Goldilocks Zone,” and making its year only 11 Earth-days. For more information about this discovery, see: https://www.sciencedaily.com/releases/2022/02/220210085019.htm.

ASTRONOMY FYI

Not News, Rather “Olds!” Sciencedaily.com posted an item recently about Edwin Hubble and his use of the Cepheid period-luminosity yardstick, developed in large part by Henrietta Swan Leavitt using stars in the SMC, to determine that the Andromeda Galaxy is a separate grouping much farther away from the Milky Way. See the piece here: https://www.sciencedaily.com/releases/2025/01/250115165531.htm . Note that the Great Smithsonian Debate of 1920 was mentioned; see also: https://www.airandspacethisweek.com/assets/pdfs/20220425 The Great Debate of 1920.pdf.

“Planet 9” Revisited: Observations of “Extreme Trans-Neptunian Objects” and the determination of their orbit parameters perhaps point to the influence of another, as yet undiscovered, dwarf planet in the outer Solar System, in addition to the “seven dwarfs” in the recent Item of the Week. Enthusiasts wanting to return to the day of a planetary Pluto call it “Planet 9,” but there is no doubt the IAU would disagree. Computer modeling suggests the hypothesized body would be 5-10 x Earth’s mass and orbit the Sun at a distance of on the order of 550 AU. The idea of a larger ETNO has been around for some time, and something may be needed to explain the observed alignment of the perihelia of some ETNOs.For a summary of this work, see: https://www.astronomy.com/science/does-planet-nine-exist; for the paper in Astronomy and Astrophysics, see: https://www.aanda.org/articles/aa/full_html/2024/12/aa50124-24/aa50124-24.html

Polynesian Navigation: The two Moana Disney movies have sparked interest in the skill of the Polynesian navigators. The Phys.org website posted a piece on Christmas day about it; see: https://phys.org/news/2024-12-disney-moana-characters-stars-astronomer.html. Polynesian traditional navigation was also the topic of a previous A+StW Item of the Week, see: https://www.airandspacethisweek.com/assets/pdfs/20200525%20TheStarofGladness.pdf.

Parker Solar Probe at 0.04 AU (!): The PSP made its closest approach ever to the Sun last week, passing a mere 3.8 million miles from the “top” of the Sun’s photosphere while it endured the 2,500 °F temperatures there. Talk about fireworks to celebrate the Heliophysics Big Year with yet another success for the PSP! Data is has acquired have allowed a better understanding of the high degree (sorry) of heating in the solar corona and the nature and acceleration of the solar wind. For more on this latest success: https://phys.org/news/2024-12-nasa-parker-solar-probe-survives.html.

IN THE SKY THIS WEEK

Sun: The Sun has an ~11-year cycle of sunspot activity. The last minimum period was in late 2020; the next maximum has just now been reached. Peak conditions could persist for the next year, so expect more sunspots, CMEs, and auroral displays in the coming months! NOAA’s 30-Minute Aurora Forecast: https://www.swpc.noaa.gov/products/aurora-30-minute-forecast.

Nova Watch: No, I’m not promoting the really good PBS series, I’m talking about T Coronae Borealis, a recurring nova. It’s usually about magnitude +10, not exactly a target for most backyard astronomers. However, every 80 years or so, it goes nova, becoming as bright as Alphecca, the brightest star in the Northern Crown (Corona Borealis). The last time it blew was in 1946, and its starting to show the same signs it did back then before it brightened.

I would suggest you become familiar with the look of this particular constellation so you can see the change for yourself when it happens. You can find out more about it at: https://skyandtelescope.org/astronomy-news/observing-news/this-weeks-sky-at-a-glance-june-7-16 . There is a link within to a 2016 Sky & Telescope article by Bob King that shows you how to find T CrB at its normal brightness. There’s even a more recent S&T piece that will help you find the “Blaze Star”: https://skyandtelescope.org/astronomy-news/is-the-blaze-star-about-to-blow-you-may-be-the-first-to-know. We’ll need a little luck, since the maximum brightness of T CrB will only last a few hours. See details of its variability at: https://apps.aavso.org/webobs/results/?star=000-BBW-825&num_results=200. 

A Helpful Tip from Dr. Steve: If you do an Internet search on “Blaze Star,” be sure you don’t channel your inner Ringo and spell it with two “r”s. Just ask Governor Earl Long….

Moon: The Moon reaches First Quarter at 9:52 AM EDT on Sunday, May 4; Full Moon occurs at 12:56 AM EDT on Tuesday, May 13 (aka the “Flower Moon”) with the Moon very near Spica.

Mercury is too close to the Sun to be seen.

Venus and Saturn are rising higher in the morning twilight sky, rising about two hours before sunup. Venus dominates at -4.7, while Saturn, lying to the right of Venus, is 250x fainter (+1.3).

Mars reached opposition on January 15, has faded a bit (+1.0). It continues to move slowly to the left of Pollux, and now lies in Cancer.

Jupiter (-2.0) lies near the horns of Taurus. 

Uranus is too close in the sky to the Sun to be seen.

Neptune (+8.0) is in Pisces, rising before the Sun but very difficult to see in the twilight.

COMETS

Comets (presently brighter than +10):

C/2025 F2 SWAN is a new comet that has “swum into our ken.” It’s presently shining at +8, lying close to Andromeda’s head in the Great Square as this half-month period begins. It will move above Aries into the Hyades by the first week of May, but it has failed to meet brightness expectations, and had faded to ~+10 by the time it reached perihelion. It is now too close to the Sun to be seen. For more about Comet SWAN, see: https://skyandtelescope.org/astronomy-news/new-comet-swan-now-visible-in-small-scopes.

C/2024 G3 ATLAS put on quite a show as it approached perihelion, at least for observers in the southern hemisphere. It is still visible down under, now shining at about +9. The comet’s nucleus shed some pieces during its perihelion passage; Sky & Telescope ran an article showing the changes in the comet’s appearance. 

No other comets are anywhere near +10.

For info on comets currently visible, see: http://www.aerith.net/comet/weekly/current.html.

SATELLITES NEXT WEEK

International Space Station

There are 31 overpasses of the ISS in the first half of May for those of you in the DC area. Two are outstanding, six are good (culminate higher than 30°), and the rest are unfavorable.

Thursday, May 8: The ISS will appear at 4:50 AM EDT, 10° above the NW horizon, then rise though the handle of the Big Dipper to an altitude of 76°, near Deneb, then descend to 10° above the SE horizon, where it will disappear.

Thursday, May 8: The ISS will appear at 9:36 PM EDT, 10° above the SSW horizon, then rise closely past the Moon to an altitude of 49°, in Virgo, then descend past Arcturus to 18° above the ENE horizon, where it will disappear.

Friday, May 9: The ISS will appear at 4:02 AM EDT, 10° above the NW horizon, then rise past the Pointers to an altitude of 44°, in Cepheus, then descend through Pegasus to 10° above the ESE horizon, where it will disappear.

Friday, May 9: The ISS will appear at 10:21 PM EDT, 10° above the W horizon, near Procyon, then rise past Castor to an altitude of 32°, in Camelopardalis, then descend through Cepheus to 10° above the NE horizon, where it will disappear.

Saturday, May 10: The ISS will appear at 4:51 AM EDT, 10° above the WNW horizon, then rise past Arcturus to an altitude of 33°, in Ophiuchus, then descend through Sagittarius to 10° above the SSE horizon, where it will disappear.

Saturday, May 10: The ISS will appear at 9:33 PM EDT, 10° above the WSW horizon, then rise closely past Procyon to an altitude of 53°, then descend through the handle of the Little Dipper to 10° above the NE horizon, where it will disappear.

Monday, May 11: The ISS will appear at 8:45 PM EDT, 10° above the SW horizon, near Sirius, then rise through Hydra and Leo to an altitude of 87°, then descend closely past Alkaid to 10° above the NE horizon, where it will disappear.

Wednesday, May 13: The ISS will appear at 8:45 PM EDT, 10° above the W horizon, near Orion, then rise past Jupiter and Capella to an altitude of 34°, then descend to 10° above the NE horizon, where it will disappear.

There are 35 overpasses of the ISS in the first half of May for those of you in the Colorado Springs area. Two are outstanding, four are good (culminate higher than 30°), and the rest are unfavorable.

Monday, May 5: The ISS will appear at 5:10 AM MDT, 10° above the NW horizon, then rise closely past the Pointers to an altitude of 33°, in Cassiopeia, then descend through Andromeda to 10° above the E horizon, near Venus, where it will disappear.

Wednesday, May 7: The ISS will appear at 5:11 AM MDT, 10° above the NW horizon, then rise closely past Alkaid to an altitude of 89°, very near Vega, then descend past Delphinus to 10° above the SE horizon, where it will disappear.

Thursday, May 8: The ISS will appear at 4:23 AM MDT, 10° above the NW horizon, then rise closely past the Pointers to an altitude of 52°, in Cepheus, then descend through Pegasus to 10° above the ESE horizon, where it will disappear.

Friday, May 9: The ISS will appear at 3:35 AM MDT, 10° above the NW horizon, then rise past Arcturus to an altitude of 32°, in Ophiuchus, then descend through Sagittarius to 10° above the E horizon, where it will disappear.

Saturday, May 10: The ISS will appear at 4:23 AM MDT, 10° above the WNW horizon, then rise past Arcturus to an altitude of 50°, in Ophiuchus, then descend through the Scutum star clouds to 10° above the SSE horizon, near Vega, where it will disappear.

Saturday, May 10: The ISS will appear at 9:05 PM MDT, 10° above the SW horizon, then rise closely past Mars to an altitude of 81°, below the bowl of the Big Dipper, then descend past the head of Draco to 10° above the NE horizon, near Vega, where it will disappear.

Hubble Space Telescope

There are no visible overpasses of the HST during the first half of May for those of you in the greater DC area.

There are no visible overpasses of the HST during the first half of May for those of you in the Colorado Springs area.

To find out about satellite overpasses in your area, see https://heavens-above.com (set your own location in the upper-right corner).

Continue the Heliophysics Big Year Celebration! NASA’s Science Mission Directorate comprises four divisions: Astrophysics, Heliophysics, Planetary Science, and Earth Science. From time to time, a division will institute a year or so long outreach effort. When I was at HQ, the emphasis was on the “Year of the Solar System.” Now, we are in the middle of an 18-month “Heliophysics Big Year.” The 2024 total Solar eclipse was one of the big events of the Big Year, and the ongoing data from the Parker Solar Probe, the Solar Dynamics Observatory, and other assets make for good engagement material. Free Heliophysics and Math Webinars are available, too; find out more at: https://science.nasa.gov/learning-resources/science-activation/celebrate-the-heliophysics-big-year-with-free-heliophysics-and-math-webinars-from-nasa-heat. And, of course, check out the recent Item of the Week about the Solar and Heliospheric Observatory! [Didja know that there are 27 spacecraft in 20 missions in Space right now observing the Sun? Not all of them are NASA’s, but that’s still a lot!]

Dark Energy Might Not Even Exist! A team of scientists at New Zealand’s University of Canterbury have published a model of the early Universe in which expansion is not uniform. “The new evidence supports the "timescape" model of cosmic expansion, which doesn't have a need for dark energy because the differences in stretching light aren't the result of an accelerating universe but instead a consequence of how we calibrate time and distance.” For more info, see the article from which the quote came, at: https://phys.org/news/2024-12-dark-energy-doesnt-lumpy-universe.html.

Without Infrastructure, Little is Possible: A truism in many contexts, including astronomy. For example, images from the James Webb Space Telescope dazzle professional astronomers and the public alike. The really-complex-yet-extremely-successful satellite is a marvel of engineering design and construction (as only NASA can!). But JWST would be of no value without the supporting infrastructure here on Earth that receives the information from its instruments.

Downlinks of data are always of paramount importance, but communicating with satellites in LEO or Geosynchronous orbit is simple compared with receiving data from JWST, which orbits the Sun-Earth L2 point, a million miles away. NASA’s Deep Space Network, originally built 60 years ago to ensure continuous radio contact with early manned spacecraft, is still up to the task! Although I’d bet that the electronics of their receivers and transmitters may have had an upgrade or two over the decades!

The DSN is an engineering marvel. For a summary, see here; for the DSN website, see here; and if you want to see whose signal the DSN is receiving, see here.

TWSftUoTtCBDftSoTiFoOT

The World Society for the Understanding of Things that Can Be Understood from the Study of Things in Front of Other Things says: An astonishing amount of Science can be conducted via the Study of Things in Front of Other Things! Examples range from the confirmation of Relativity by observations made during a total solar eclipse to asteroid shapes to rings around Uranus to planets of other Suns. Since many exoplanets have been discovered when they were “in front of other things,” all exoplanet and SETI news and info will be covered in the section below.

Exoplanet K2-18b: There was a recent splash in the media recently about astronomers possibly detecting conditions indicative of biological activity on exoplanet K2-18b, a “mere” 120 light-years or so away. What’s up with that?

Astronomers have found thousands of exoplanets that pass between us and their stars, causing a small but detectable drop in brightness. The technique and equipment have advanced to the point where they can now determine the composition of the atmosphere of some exoplanets. When they pass in front of their star, specific gases absorb specific wavelengths of light and re-emit them in all directions. From our perspective, those exact wavelengths are “missing,” a form of chemical “fingerprints.” Sounds wild, but that’s how astronomers discovered the element helium and how they can measure the composition of stars (see also here). 

K2-18b was found by the transit method, and when the JWST was used to observe the transits in detail astronomers found the spectral signature of two gases, dimethyl sulfide and dimethyl disulfide. On Earth, those two compounds are quite rare, and the only known we that they are produced in nature is as a byproduct of the metabolism of biological organisms. In addition, we know that K2-18b lies in its star’s “Goldilocks Zone,” meaning its surface temperature is likely in the range where water is liquid at least part of its orbit. It is nine times more massive than the Earth, but oddly less dense, meaning much of its mass is unusually light for a planet. One possibility of the cause of its low density is that it has a large component of something, like water, that is lighter than rock. Are those chemicals biological in origin? Big Question!

For a reasonable analysis of this issue, see: https://news.stanford.edu/stories/2025/04/four-questions-laura-schaefer-alien-life-k2-18b; the original announcement from the University of Cambridge is here: https://www.cam.ac.uk/stories/strongest-hints-of-biological-activity.

Meet Pandora! NASA is preparing a mission named “Pandora” that will examine 20+ known exoplanets to determine the composition of their atmospheres. The mission reached an important milestone recently with the completion of the main spacecraft bus. Pandora’s primary instrument is a very sensitive detector of the near-infrared part of the spectrum. It was the back-up for the identical detector aboard the JWST. Not only will it be able to ascertain the compositions of known exoplanets, its data will help calibrate the data from the same instrument on JWST, which can see much farther in both Space and time. The linked-to page also gives access to material about Pandora from NASA’s Scientific Visualization Studio. For more information, see: https://science.nasa.gov/centers-and-facilities/goddard/nasas-pandora-mission-one-step-closer-to-probing-alien-atmospheres.

Constraints on Extraterrestrial Life?  The transit method used to detect almost all known exoplanets (e.g. using TESS, Kepler) works very well, but suffers from a huge selection effect. Large planets orbiting very close to their stars are readily detected, but a planetary system like our own would be almost impossible to detect that way. After all, how often do we see Mercury or Venus in transit of our own Sun? For a transit of the Sun to be seen at interstellar distances, the observer would have to be very close to the Plane of the Ecliptic. Therefore, most exoplanets detected to date orbit red dwarfs very closely. Life on them could be adversely impacted by the extreme space weather associated with many red dwarfs.

A new study using data from NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton satellite were used to assess the environment in which known exoplanets such as Wolf 359 orbit. Wolf 359 was a good test subject. It is suspected of having two exoplanets, and it is only 7.8 light-years away. Chandra and XMM-Newton can make more detailed measurements of it than they can from more distant exoplanet systems. The assessment of X-ray and Extreme UV radiation suggest that for life to exist in such a system, it would have to be on an exoplanet that has a dense atmosphere and be fairly far away from its star. The “Goldilocks Zone” from Wolf 359 was determined to be about 15 million miles and fairly narrow, between the likely orbits of the two as-yet-confirmed exoplanets. And if the regular X-ray environment made prospects for life iffy, Wolf 369 also spews very powerful and destructive X-ray flares on a frequent basis.

For more information about this research, see: https://www.nasa.gov/general/exoplanets-need-to-be-prepared-for-extreme-space-weather-chandra-finds.

A Primer in Transits: NASA posted an introductory piece to the TWSFTUOTTCBDFTSOTIFOOT favorite of planetary transits here. Detecting the small drop in light from a star when its exoplanet transits across its face is one of the primary means of detecting exoplanets, enabled by ground-based observation and satellites like Kepler and TESS. While the transit method has produced many exoplanet findings, but other methods are useful, too (see immediately below).

Interesting Exoplanet: LHS 1140 is a red dwarf star located 48 light-years from Earth in the constellation Cetus. It has a “super-Earth” exoplanet orbiting in its “Goldilocks Zone” and a bulk density that suggests that ~10% of its mass is water. It’s been known for some time, but only recently have the system’s physical properties been determined accurately. Its rotation is tidally-locked with its year, meaning that it always keeps the same face pointing sun-ward; estimates of temperatures there are a balmy 70°F! For a summary of our study of this interesting place, see here: https://earthsky.org/space/ocean-world-lhs-1140-b-exoplanets-astrobiology; for a paper about it in The Astrophysical Research Letters, see: https://iopscience.iop.org/article/10.3847/2041-8213/ad5afa!

Confirmed Exoplanets: Now 5,502! Over 31 years ago, the first two confirmations of planets orbiting another star were made. It was a strange system, since they were both orbiting a pulsar! Now, the announcement of six new confirmations has pushed the total of definite exoplanets to 5,502. For of the new finds were made by the transit method, one by the radial velocity method, and one was made by direct observation.

SEARCH FOR HABITABLE EXOPLANETS

Habitable Worlds Observatory: Yes, Virginia, there will be such a thing in the future. The 2020 Astronomy Decadal Survey strongly recommended that NASA “develop a 6-meter Space telescope capable of high-contrast observations in optical, infra-red, and ultraviolet wavelengths.” Its primary mission will be to examine 25 different exoplanets in detail, all in their star’s “Goldilocks Zone,” searching for biosignatures. Knowing which stars to choose is obviously of great importance. That work is presently underway; NASA’s Exoplanet Exploration Program has developed a list of 164 candidates to date, based on five selection criteria: stellar composition, photometric values, flare rate, variability, and potentially-sterilizing X-ray emissions. For more information on this project, see: https://phys.org/news/2024-01-astronomers-habitable-worlds-observatory.html and https://science.nasa.gov/astrophysics/programs/habitable-worlds-observatory.

SEARCH FOR INTELLIGENT LIFE ELSEWHERE

Part 1: UCLA’s Jean-Luc Margot is the founder of UCLA SETI’s “Are We Alone in the Universe?” project. Their mission is to detect “technosignatures by searching individual systems. Dr. Margot teaches a graduate course in SETI, and he had his students use TESS data for the closer known exoplanets to narrow the search for such emissions in great detail. No provable technosignatures were seen. Even though the smally sample observed didn’t show emissions, the skills developed by the students (e.g. signal processing, telecommunications, and statistics and other data analysis tools) will no doubt improve their academic success.

Part 2: Traditional SETI tactics, like Dr. Margot’s project, is one way to search. The Breakthrough Listen program (which uses citizen scientists) takes a different approach. Rather than look at relatively-close systems, they are using the Green Bank (West Virginia) and Parkes Murriyang radio telescopes to look for very high powered technosignatures, an entire galaxy at a time. For more on this program and strategy, see: https://phys.org/news/2023-12-breakthrough-scans-entire-galaxies-extremely.html.

Part 3: NASA has produced a six-part on-line series on how it is searching for life in the cosmos. If you are interested in the real science behind this topic, then check out these episodes! Part 1: Beginnings: Life on Our World and Others; Part 2: Life on Other Planets: What is Life and What Does It Need?; Part 3: The Hunt for Life on Mars – and Elsewhere in the Solar System; Part 4: “Life” in the Lab; Part 5: Searching for Signs of Intelligent Life: Technosignatures (see also this week’s Gravity Assist entry in the Solar System section); and Part 6: Finding Life Beyond Earth: What Comes Next?

What Happens After We Discover Life Elsewhere? Mary Voytek, Director of NASA’s Astrobiology Program, has some interesting thoughts on the subject. Check them out at: https://exoplanets.nasa.gov/news/1766/finding-life-beyond-earth-what-comes-next!

Exoplanet Travel Bureau is NASA’s source for whimsical travel posters showcasing various exoplanets as tourist destinations and other exoplanet information. See: https://exoplanets.nasa.gov/alien-worlds/exoplanet-travel-bureau!

ASTRONOMY LINKS AND OTHER INFORMATION

Astronomy.com: https://astronomy.com/news

Phys.org: https://phys.org/space-news/astronomy

Space.com: https://www.space.com/news

Science Daily: https://www.sciencedaily.com/news/space_time/astronomy

Sky and Telescope: https://skyandtelescope.org/astronomy-news

NASA Exoplanet Exploration News: https://exoplanets.nasa.gov/news