Launches
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December 18 in spaceflight
Wikipedia records 6 spaceflight and astronomy events on December 18. Below are the pictures NASA published on December 18 in 5 different years — each one taken or released on this exact date.
Recorded events
IN THE RECORD6ENTRIES
Spaceflight and astronomy entries from Wikipedia's record of this date, oldest first — from 1958 onward.
Pictures from this date
PUBLISHED5IMAGES
NASA's Astronomy Picture of the Day for December 18, one per year. Some are public domain and some belong to the photographer — each says which.
Published on December 18
NASA’s Astronomy Picture of the Day, for this calendar date in each of the last several years.
2025
Jupiter and the Meteors from Gemini
Jupiter, the Solar System's ruling gas giant, is the brightest celestial beacon at the center of this composite night skyscape. The scene was constructed by selecting the 40 exposures containing meteors from about 500 exposures made on the nights of December 13 and 14, near peak activity for this year's annual Geminid meteor shower. With each selected exposure registered in the night sky above Alentejo, Portugal, planet Earth, it does look like the meteors are streaming away from Jupiter. But the apparent radiant of the Geminid meteors is actually closer to bright star Castor, in the shower's eponymous constellation Gemini. In this frame that's just a little above and left of the Solar System's most massive planet. Still, the parent body of Geminid meteors is known to be rocky, near-Earth asteroid 3200 Phaethon. And the orbit of Phaethon itself is influenced by the gravitational attraction exerted by massive Jupiter, in concert with planets of the inner Solar System.
© David Cruz — used with the credit NASA publishes
2024
NGC 660: Polar Ring Galaxy
What kind of strange galaxy is this? This rare structure is known as a polar ring galaxy, and it seems to have two different rings of stars. In this galaxy, NGC 660, one ring of bright stars, gas, and dark dust appears nearly vertical, while another similar but shorter ring runs diagonally from the upper left. How polar ring galaxies obtain their striking appearance remains a topic of research, but a leading theory holds that it is usually the result of two galaxies with different central ring planes colliding. NGC 660 spans about 50,000 light years and is located about 40 million light years away toward the constellation of the Fish (Pisces). The featured image was captured recently from Observatorio El Sauce in Chile.
© Mike Selby — used with the credit NASA publishes
2023
The Same Color Illusion
Are squares A and B the same color? They are! To verify this, either run your cursor over the image or click here to see them connected. The featured illusion, an example of the same color illusion, illustrates that purely human perceptions in science may be ambiguous or inaccurate, even such a seemingly direct perception as relative color. Similar illusions exist on the sky, such as the size of the Moon near the horizon, or the apparent shapes of astronomical objects. The advent of automated, reproducible measuring devices such as CCDs have made science in general and astronomy in particular less prone to, but not free of, human-biased illusions. APOD Year in Review (2023): RJN's Night Sky Network Lecture
NASA · public domain
2022
25 Brightest Stars in the Night Sky
Do you know the names of some of the brightest stars? It's likely that you do, even though some bright stars have names so old they date back to near the beginning of written language. Many world cultures have their own names for the brightest stars, and it is culturally and historically important to remember them. In the interest of clear global communication, however, the International Astronomical Union (IAU) has begun to designate standardized star names. Featured here in true color are the 25 brightest stars in the night sky, currently as seen by humans, coupled with their IAU-recognized names. Some star names have interesting meanings, including Sirius ("the scorcher" in Latin), Vega ("falling" in Arabic), and Antares ("rival to Mars" in Greek). You are likely even familiar with the name of at least one star too dim to make this list: Polaris. Almost Hyperspace: Random APOD Generator
© Tragoolchitr Jittasaiyapan — used with the credit NASA publishes
2021
Stephan's Quintet
The first identified compact galaxy group, Stephan's Quintet is featured in this eye-catching image constructed with data drawn from the extensive Hubble Legacy Archive. About 300 million light-years away, only four of these five galaxies are actually locked in a cosmic dance of repeated close encounters. The odd man out is easy to spot, though. The interacting galaxies, NGC 7319, 7318A, 7318B, and 7317 have an overall yellowish cast. They also tend to have distorted loops and tails, grown under the influence of disruptive gravitational tides. But the predominantly bluish galaxy, NGC 7320, is closer, just 40 million light-years distant, and isn't part of the interacting group. Stephan's Quintet lies within the boundaries of the high flying constellation Pegasus. At the estimated distance of the quartet of interacting galaxies, this field of view spans about 500,000 light-years. But moving just beyond this field, up and to the right, astronomers can identify another galaxy, NGC 7320C, that is also 300 million light-years distant. Including it would bring the interacting quartet back up to quintet status.
NASA · public domain
What happened on December 18
1958
The United States launched SCORE (rocket pictured), the world's first communications satellite.
SCORE (satellite) ↗
1966
Epimetheus, one of the moons of Saturn, was discovered, but was mistaken for Janus; it took twelve years to determine that they are two distinct objects sharing the same orbit.
Epimetheus (moon) ↗
1973
Soviet Soyuz Programme: Soyuz 13, crewed by cosmonauts Valentin Lebedev and Pyotr Klimuk, is launched from Baikonur in the Soviet Union.
Soyuz programme ↗
1999
NASA launches into orbit the Terra platform carrying five Earth Observation instruments, including ASTER, CERES, MISR, MODIS and MOPITT.
NASA ↗
Sources and licences
Event text and thumbnails come from Wikipedia and are used under CC BY-SA 4.0. Images are drawn only from Wikimedia Commons, which does not accept non-free content — each thumbnail links to its file page, where its licence and author are recorded.
Launch records are from The Space Devs’ Launch Library 2. This archive is still being mirrored, so some days are incomplete. Pictures are NASA’s Astronomy Picture of the Day; NASA imagery is generally not subject to copyright, but individual APOD entries are frequently the property of the photographer, and each caption says which applies.
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Cosmos — Carl Sagan
Still the best single argument for why any of this matters, and it leaves the arithmetic in. For a reader who wants the science, not just the awe.
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Pale Blue Dot — Carl Sagan
The case for leaving Earth, written by someone unsentimental about how hard that is. Suits readers who want the argument rather than the poster.
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Project Hail Mary — Andy Weir
Hard-SF problem solving in The Martian's key — for anyone who liked the engineering more than the peril. The only novel on this list.
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