3278: Vera Rubin Observatory

Vera Rubin Observatory

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Title text: 'Spurious signals from the kitchen' is harder for an optical telescope than a radio one, but with enough determination and creativity, I believe it's possible.

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Explanation

This shows a bingo card of various items observed or potentially observable using the Vera C. Rubin Observatory, an astronomical observatory located in Chile. The observatory features the largest (as of 2026) digital astronomical camera, and began regularly collecting scientific data shortly before the publication of this comic. Some of the listed possibilities are highly likely, some are quite improbable, and some are entirely ridiculous. The observatory has released a genuine bingo card game, featuring more likely objects, intended for educational purposes.

A table of the items on the comic's bingo card is shown below:

#	Item	Could be checked off now?	Likely to be checked off in the future?	Explanation
1	Black hole tidally disrupting a star	No	Maybe	A few days before this comic, a paper describing the detection of a tidal disruption event was published. However, it was detected by the Palomar Observatory, not Rubin.
2	Planet Nine	No	Unlikely	This is a hypothetical planet in the distant reaches of the Solar System, whose gravitational effects could explain the orbits of some extreme trans-Neptunian objects (see further entries below). Before it was redesignated as a dwarf planet, Pluto was considered the ninth planet.
3	Remnants of a former Milky Way companion galaxy	No	Maybe	Galaxies are usually found in local clusters that are (on a galactic scale) relatively close to each other, and can be identified as orbiting each other. This includes the cluster which contains our own galaxy; there are several known 'companions' to the Milky Way. The Milky Way is also thought to have grown by many mergers with smaller galaxies, one of which was identified earlier in the year this comic appeared, and more may be identified in the future. This square could be describing a heretofore unidentified no-longer-active galaxy, still out there as an unnoticed companion. More likely, though, it is intended to mean a smaller galactic body that came too close and was 'cannibalised'. The evidence for this might be a distribution of stars in our galaxy whose angular and radial motions, compared to most of the adjacent stars in the galaxy, along with their metallicity, indicate that they (or at least some of their pre-stellar material) originated from somewhere outside our galaxy.
4	10,000 new trans-Neptunian objects	No	Yes	Trans-Neptunian objects (TNOs) are celestial bodies orbiting the Sun beyond Neptune. The Vera Rubin Observatory is predicted to discover over 37,000 TNOs by the mid-2030s. For comparison, only about 5,000 TNOs had been discovered as of December 2024. The Vera Rubin Observatory began test observations in June 2025 and discovered 380 TNOs by April 2026.
5	Object on interstellar trajectory	Partly	Yes	Interstellar objects are celestial bodies travelling through interstellar space, not gravitationally bound to any star, including our Sun. While most interstellar objects we see are many light years away, some may occasionally come close enough to Earth for us to study in detail. These close-passing interstellar objects are most likely to be small asteroids or comets. Only three such objects have been discovered to date: 1I/ʻOumuamua, 2I/Borisov, and 3I/ATLAS. One of the Vera Rubin Observatory's goals is to efficiently detect interstellar objects thanks to its wide field of view, which will help astronomers figure out the abundance and properties of the interstellar object population. The Vera Rubin Observatory actually recorded 3I/ATLAS several days before its discovery, though this was not found until 3I/ATLAS had been discovered with other telescopes. This highlights the observatory's potential to discover new interstellar objects.
6	Star being eclipsed by weird object	No	Maybe	The Vera Rubin Observatory will routinely measure the brightnesses of stars over time, producing a light curve. Many stars change brightness over time, though by different amounts and speeds. Stars generally dim because of starspots rotating in and out of view, stellar pulsation of their temperature and radius, clouds of dust passing in front of them, or orbiting planets and stars. In rare cases, a star may dim so much that it ends up temporarily disappearing for a few hours to a few years. Such events are believed to be caused by large objects (radii spanning millions of kilometers) eclipsing the star. Such large objects may be a dense dust cloud, such as the one responsible for the 2019-2020 dimming of Betelgeuse, or a protoplanetary disk surrounding a dim planet, brown dwarf, or star. These dimming events may either repeat once every few years, if the eclipsing object is orbiting the star, like in Epsilon Aurigae; never repeat, if the eclipsing object is not orbiting the star, like J1407b; or occur irregularly, as happened with Boyajian's Star (aka Tabby's Star), which is thought to have large amounts of thick dust and a giant planet orbiting in front of it.
7	Secret military satellite	No	Maybe	During the development of the Vera Rubin Observatory, an unspecified United States agency raised concerns that the observatory would detect spy satellites, posing a risk to national security. These concerns were addressed after a 2023 meeting with the observatory's director Željko Ivezić. The observatory now has an automated system that checks for any spy satellites in images, and deliberately delays their access to astronomers for three days if any were found.[1][2] The VRO alert system also does not publish objects moving across the sky faster than 10 degrees per day to avoid spurious notifications of low-orbiting satellites (and in particular secret military satellites).
8	Kuiper Belt object that's a surprising color	No	Maybe	Kuiper belt objects (KBOs) are icy celestial bodies found in the Solar System's Kuiper belt, the home of Pluto, beyond the orbit of Neptune. KBOs are generally found with optical colors ranging from "blue"/"neutral" to "red" to "very red". (Note that to the human eye, these colors would actually range from gray to brown.) The Vera Rubin Observatory can distinguish the optical colors of astronomical objects by measuring their brightness through multiple visible light filters. These colors translate to a specific surface composition, with gray colors indicating abundant water ice and red colors indicating abundant organic compounds ("tholins"). Certain colors and compositions may be found more frequently than others in different parts of the Kuiper belt (e.g. KBOs with low-inclination circular orbits tend to be very red), which gives astronomers hints to how the Kuiper belt evolved in the Solar System's early history. If a KBO has a color and composition not matching any of this, it might suggest a different origin from the typical KBOs, which would be exciting for astronomers and space enthusiasts. For example, the KBO (120216) 2004 EW95 has a dark gray, carbon-rock-rich surface more like that of asteroids than icy KBOs, which makes astronomers think that it might be an ejected asteroid. In addition, some KBOs may have unusually "blue" (gray) surfaces with very high albedos (making their surfaces highly reflective like white ice)—such objects would be considered members of the Haumea family, which are believed to be fragments flung off from the dwarf planet Haumea after a catastrophic collision billions of years ago.
9	Mars-sized TNO	No	Maybe	Trans-Neptunian objects (TNOs) are celestial bodies orbiting the Sun beyond Neptune. The largest one (by volume) found to date is Pluto, which is substantially smaller than Mars. If there is an undiscovered Mars-sized TNO, then it must be dim (apparent magnitude > 24) and extremely far away (over 500 to 1,000 AU from the Sun) in order to remain undetected by sky surveys before the Vera Rubin Observatory. According to a 2020 study, thousands of Pluto- to Mars-sized planets may have once existed in the early Solar System, but ended up ejected by larger planets, leaving (it is estimated) less than ten remaining in the outer Solar System.
10	Local group supernova	No	Maybe	The observation of a supernova in the Local Group (the group of galaxies that contains our own Milky Way) by modern telescopes would provide an unprecedented wealth of information about their dynamics. Astronomers have been waiting for such an event for decades (as referenced in 3208: SNEWS). The only two Local Group supernovae observed since the invention of telescopes were SN 1885A in Andromeda and SN 1987A in the Large Magellanic Cloud.
11	Spurious signal from observatory kitchen	No	No	This is an allusion to an incident at the Parkes Observatory where their radio telescope detected signals that turned out to be radiation from a microwave oven. This was previously referenced in 2886: Fast Radio Bursts. It could also be in reference to 3275: Calibration Nobel, although calibration would probably not help here as much as microwave-turning-off skills. The title text points out that the Rubin observatory, housing an optical telescope rather than radio, would be unlikely to detect signals like this, but Randall thinks some clever technique could be used to get it to observe them. There is no obvious reason why anyone would want to create such artefacts, beyond filling in this bingo card.
12	Glitch in alert system spams all astronomers	No	No	The VRO alert stream offers near-real time notification about brightness or position changes in images taken by the telescope. Astronomers can subscribe to downstream 'alert brokers' to filter the subset of alerts that are of interest to them or their automated processing pipelines. As approximately seven million alerts are generated every night, a glitch that sent an alert (or multiple alerts) to all astronomers (including ones who did not sign up) is likely to be massively annoying and disruptive.
13	Space (free)	Yes	Yes	The center square of a 5×5 bingo card is typically marked as a "free space", meaning it automatically counts toward the goal (typically 5-in-row). This square makes a pun by labeling the center square with the requirement "space"; since the telescope is virtually guaranteed to find space, the square is essentially "free". Free space in this context may mean space in which the telescope observes no objects, which could be something very interesting given how there should be many things to be seen just about everywhere you look, even in the apparent 'gaps'.
14	Earth-sized TNO	No	Unlikely	See 'Mars-sized TNO' above. Since Earth is significantly larger than Mars, any discovery of this type would be even more exciting. Some astronomers have hypothesized the existence of an Earth-sized TNO in place of Planet Nine, as in this 2023 study.
15	Defunct spacecraft	No	Maybe	A reference to space pollution, the phenomenon of manmade objects in space (such as spacecraft) that are defunct, but have not disintegrated into atmospheric matter (for instance, by burning up on reentry) remaining in space. A specific form of space pollution, Kessler syndrome, has been referenced in xkcd before. In addition to these, survey telescopes like Pan-STARRS and Vera Rubin can misidentify spacecraft—defunct or not—as near-Earth objects, especially if their trajectories are not well-documented. An example of such an incident is 2020 SO, a piece of a 1966 rocket that was mistakenly identified as a near-Earth object by Pan-STARRS in September 2020. A subset of space trash consists of pieces of foil or insulation in high orbits that are light and easily perturbed by solar radiation pressure; such 'high area-to-mass ratio objects' (HAMOs) or empty trash bag objects' (ETBOs), are regularly reported as spurious new asteroids, due to not being recorded in existing satellite catalogues such as those from the United States Space Force. These could conceivably be moving slowly enough at apogee to generate alerts from Rubin.
16	Surprising number of small galaxies	No	Maybe	Modeling work suggests that many undetected small galaxies exist, including approximately 100 close to the Milky Way.
17	Neutron star merger	No	Yes	Neutron star mergers have been observed by gravitational wave detectors LIGO and Virgo, which are more suited for such an observation. Some, such as GW170817, have been subject to multi-messenger astronomy, in which electromagnetic (light, radio, X-ray, etc.) and other telescopes were trained on the event after its detection via gravity waves. The Vera Rubin Observatory will be used for such work in the future.
18	New supernova constraints on dark energy	No	Yes	A study of 1500 supernovae was used to constrain the expansion of the universe, which is thought to be driven by dark energy. The Vera Rubin Observatory is expected to detect many more supernovae — approximately 10 million over a 10-year span — and thus provide much tighter constraints on dark energy.
19	New dwarf planet bigger than Pluto/Eris	No	Maybe	Pluto is the largest known dwarf planet by radius and volume, whereas Eris is the largest known dwarf planet by mass. Both dwarf planets have pretty similar radii, although Eris is only a few kilometers smaller. If there is an undiscovered dwarf planet bigger than those two, than it must be quite dim (apparent magnitude > 24) and extremely far away (over 500 to 1,000 AU from the Sun) in order to remain undetected by sky surveys before the Vera Rubin Observatory. According to a 2020 study, thousands of Pluto- to Mars-sized planets may have once existed in the early Solar Solar System, but ended up ejected by larger planets, leaving less than ten remaining in the outer Solar System.
20	Lost historical comet	No	Maybe	Some comets were discovered several hundred years ago but were never seen again, either because they physically disintegrated, their orbits were too poorly known to make accurate predictions for their reappearances, or because their orbital periods are simply too long for there to have been another opportunity to observe them. In the majority of cases where lost comets end up being rediscovered, they are found as faint, unremarkable asteroids—dormant husks of their former selves. An example of this is asteroid (529668) 2010 JL33, which was identified as a likely fragment of Lexell's comet (D/1770 L1, with "D" indicating the comet was destroyed).
21	5 million asteroids and comets	No	Yes	The Vera Rubin Observatory is predicted to discover over five million asteroids (near Earth and in the main asteroid belt) by the mid-2030s. For comparison, only 1.5 million asteroids had been discovered as of July 2026. The Vera Rubin Observatory began test observations in June 2025 and discovered 11,000 asteroids by April 2026.
22	50,000 near-Earth asteroids	No	Yes	The Vera Rubin Observatory is predicted to discover over 127,000 near-Earth objects (the majority of which would be near-Earth asteroids) by the mid-2030s. For comparison, about 42,000 near-Earth objects had been discovered as of July 2026. The Vera Rubin Observatory began test observations in June 2025 and discovered 33 near-Earth asteroids by April 2026.
23	Object likely to impact Earth	No	Maybe	Sentry is a monitoring system maintained by NASA to identify asteroids which have a non-negligible likelihood of impacting Earth. A previous such asteroid, the Chicxulub asteroid, was responsible for a mass extinction event, killing 75 % of all plant and animal species on Earth, most notably all non-avian dinosaur species. Another such impact would prove catastrophic to humankind, meriting an early warning and response system. While the population of asteroids large enough to cause catastrophe is small, tiny asteroids of several-meter diameter hit the Earth's atmosphere 10-100 times a year. A few of these (e.g. 2008 TC3) are discovered by ground-based surveys before they hit Earth. VRO will likely find 1-2 such impactors per year in the southern sky, with an average of 1.57 days of lead time, allowing follow-up and characterization by other observatories and correlation to any resulting meteorite falls. 2024 YR4 is an asteroid that previously held an impact rating of 3 on the Torino scale, defined as "A close encounter, meriting attention by astronomers".
24	Vera Rubin herself (faked death, stole spaceship)	No	No	Vera Rubin, the namesake of the observatory, died in 2016. This card proposes that she may have faked her death and flown out into space in secret, only to be found out and caught by the observatory named after her. This would be considered unlikely by astronomers.[citation needed]
25	Many very small dots	Yes	Yes	"Very small dots" is a pithy way to describe the objects in distant space visible from Earth. The primary purpose of an observatory is to study these 'small dots' in great detail, so in this case discovering "small dots" would be a free bingo space (except in the unusual case where it is observing space free of objects). Alternatively, this may be a reference to the Petrova Line in Project Hail Mary, which is described as "space dots", or maybe some variation on the little red dots discovered by the James Webb Space Telescope, previously referenced by the comic 3212: Little Red Dots.

Transcript

[Title:]

Vera Rubin Observatory discoveries

Bingo card

[A 5-by-5 bingo card is shown. They are as follows, left to right, by each row:]

Black hole tidally disrupting a star

Planet nine

Remnants of a former Milky Way companion

10,000 new trans-Newtonian objects

Object on interstellar trajectory

Star being eclipsed by weird object

Secret military satellite

Kuiper Belt object that's a surprising color

Mars-sized TNO

Local group supernova

Spurious signal from observatory kitchen

Glitch in alert system spams all astronomers

Space (free)

Earth-sized TNO

Defunct spacecraft

Surprising number of small galaxies

Neutron star merger

New supernova constraints on dark energy

New dwarf planet bigger than Pluto/Eris

Lost historical comet

5 million asteroids and comets

50,000 near-Earth asteroids

Object likely to impact Earth

Vera Rubin herself (faked death, stole spaceship)

Many very small dots

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Discussion

somehow I feel that you would never get bingo. 73.132.167.116 (talk) (please sign your comments with ~~~~) 29 July 15:54 2026

Maybe you would if it was over the next decade or century 2600:1700:3B93:1020:81C9:9080:A87:F649 21:13, 29 July 2026 (UTC)

"Many very small dots" might be related to "Little red dots" that were discovered by JWST. Barmar (talk) 20:09, 29 July 2026 (UTC)

I think the downward diagonal would be the easiest 115.70.50.124 21:01, 29 July 2026 (UTC)

Or maybe the left column Logalex8369 (talk) 21:07, 29 July 2026 (UTC)

I believe that the one mentioning signals coming from a kitchen may also be in reference to the recent 3275: Calibration Nobel. (Edit: fixed typo) 2600:1700:3B93:1020:81C9:9080:A87:F649 21:13, 29 July 2026 (UTC)

I feel like the entire concept for this comic was centered around the free space pun. 136.56.54.87 21:21, 29 July 2026 (UTC)

Check out the official RUBINgo game. -- Trailifox43 (talk) 21:24, 29 July 2026 (UTC) (please sign your comments with ~~~~)

Have added that to the explanation, since it seems quite likely it may have prompted the comic. 82.13.184.33 08:51, 30 July 2026 (UTC)

Grrr.... I'm mildly disappointed that this xkcd didn't mention Neptune trojans, irregular moons, active asteroids, and TNOs on weird orbits. >:Ɛ 2603:8002:BE00:8292:CD63:C4A9:21F:2BBB 04:06, 30 July 2026 (UTC)

There's only 25 boxes on a bingo card, he couldn't include everything. Barmar (talk) 14:44, 30 July 2026 (UTC)```

It's not as if there is only a single card in a game of bingo. JohnHawkinson (talk) 01:57, 31 July 2026 (UTC)

Could "planet 9" be a pun on "plan 9 from outer space"? Nosrednayduj (talk) 16:55, 30 July 2026 (UTC)

I don't think so, since it's a pretty common goal: https://en.wikipedia.org/wiki/Planet_Nine 206.193.5.5 19:11, 30 July 2026 (UTC)

Black Hat doesn't need an obvious reason to create spurious signals from the kitchen: the act itself is reason enough. "There is no obvious reason why anyone would want to create such artefacts, beyond filling in this bingo card." Martin (talk) 22:15, 30 July 2026 (UTC)

That's kind of what that sentence is saying - it would be (scientifically and otherwise) an entirely pointless, and in some ways destructive, act, outside of the goal of completing the bingo card. There's no evidence that Black Hat is involved here though. 82.13.184.33 08:17, 31 July 2026 (UTC)

How many small galaxies would be surprising? A million? A billion? Just two? Martin (talk) 22:16, 30 July 2026 (UTC)

Depends what they're doing. 82.13.184.33 15:50, 31 July 2026 (UTC)

I used 1547: Solar System Questions as a basis for the "Checked-off" column. I'm excited to see this bingo chart filled in. Do note that we can include a lightyellow "maybe" options for those items uncertain. Maplestrip (talk) 12:22, 31 July 2026 (UTC)

I still remember when I saw it still being constructed at SLAC labs and when it was still called the LSST camera... tori :3^{talk to me!} 22:22, 16 August 2026 (UTC)
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