Launches
NO DATA0MISSIONS
The launch archive is still being mirrored, so this day has no launches listed yet.
ARCHIVE // DAY OF YEAR
Wikipedia records 3 spaceflight and astronomy events on April 30. Below are the pictures NASA published on April 30 in 5 different years — each one taken or released on this exact date.
0MISSIONS
The launch archive is still being mirrored, so this day has no launches listed yet.
3ENTRIES
Spaceflight and astronomy entries from Wikipedia's record of this date, oldest first — from 1006 onward.
5IMAGES
NASA's Astronomy Picture of the Day for April 30, one per year. Some are public domain and some belong to the photographer — each says which.
NASA’s Astronomy Picture of the Day, for this calendar date in each of the last several years.

2025
Sometimes, the sky itself seems to smile. A few days ago, visible over much of the world, an unusual superposition of our Moon with the planets Venus and Saturn created just such an iconic facial expression. Specifically, a crescent Moon appeared to make a happy face on the night sky when paired with seemingly nearby planets. Pictured is the scene as it appeared over Zacatecas, México, with distinctive Bufa Hill in the foreground. On the far right and farthest in the distance is the planet Saturn. Significantly closer and visible to Saturn's upper left is Venus, the brightest planet on the sky. Just above the central horizon is Earth's Moon in a waning crescent phase. To create this gigantic icon, the crescent moon phase must be smiling in the correct direction. Dial-A-Moon: Find the Moon phase on your birthday this year
© Daniel Korona — used with the credit NASA publishes

2024
The star system GK Per is known to be associated with only two of the three nebulas pictured. At 1500 light years distant, Nova Persei 1901 (GK Persei) was the second closest nova yet recorded. At the very center is a white dwarf star, the surviving core of a former Sun-like star. It is surrounded by the circular Firework nebula, gas that was ejected by a thermonuclear explosion on the white dwarf's surface -- a nova -- as recorded in 1901. The red glowing gas surrounding the Firework nebula is the atmosphere that used to surround the central star. This gas was expelled before the nova and appears as a diffuse planetary nebula. The faint gray gas running across is interstellar cirrus that seems to be just passing through coincidently. In 1901, GK Per's nova became brighter than Betelgeuse. Similarly, star system T CrB is expected to erupt in a nova later this year, but we don't know exactly when nor how bright it will become.
© Deep Sky Collective — used with the credit NASA publishes

2023
Although its colors may be subtle, Saturn's moon Helene is an enigma in any light. The moon was imaged in unprecedented detail in 2012 as the robotic Cassini spacecraft orbiting Saturn swooped to within a single Earth diameter of the diminutive moon. Although conventional craters and hills appear, the above image also shows terrain that appears unusually smooth and streaked. Planetary astronomers are inspecting these detailed images of Helene to glean clues about the origin and evolution of the 30-km across floating iceberg. Helene is also unusual because it circles Saturn just ahead of the large moon Dione, making it one of only four known Saturnian moons to occupy a gravitational dimple known as a stable Lagrange point.
NASA · public domain

2022
A mere 600 light-years away, M44 is one of the closest star clusters to our solar system. Also known as the Praesepe or the Beehive cluster its stars are young though, about 600 million years old compared to our Sun's 4.5 billion years. Based on similar ages and motion through space, M44 and the even closer Hyades star cluster in Taurus are thought to have been born together in the same large molecular cloud. An open cluster spanning some 15 light-years, M44 holds 1,000 stars or so and covers about 3 full moons (1.5 degrees) on the sky in the constellation Cancer. Visible to the unaided eye, M44 has been recognized since antiquity. Described as a faint cloud or celestial mist long before being included as the 44th entry in Charles Messier's 18th century catalog, the cluster was not resolved into its individual stars until telescopes were available. A popular target for modern, binocular-equipped sky gazers, the cluster's few yellowish tinted, cool, red giants are scattered through the field of its brighter hot blue main sequence stars in this telescopic group snapshot. Dramatic diffraction spikes highlighting the brighter cluster members were created with string crossed in front of the telescope's objective lens.
© Drew Evans — used with the credit NASA publishes

2021
On April 25 a nearly full moon rose just before sunset. Welcomed in a clear blue sky and framed by cherry blossoms, its familiar face was captured in this snapshot from Leith, Edinburgh, Scotland. Known to some as a Pink Moon, April's full lunar phase occurred with the moon near perigee. That's the closest point in its not-quite-circular orbit around planet Earth, making this Pink Moon one of the closest and brightest full moons of the year. If you missed it, don't worry. Your next chance to see a full perigee moon will be on May 26. Known to some as a Flower Moon, May's full moon will actually be closer to you than April's by about 98 miles (158 kilometers), or about 0.04% the distance from the Earth to the Moon at perigee.
© Alice Ross — used with the credit NASA publishes
1006
SN 1006, the brightest supernova in recorded history, first appeared in the constellation Lupus.
SN 1006 ↗1897
J. J. Thomson of the Cavendish Laboratory announces his discovery of the electron as a subatomic particle, over 1,800 times smaller than a proton (in the atomic nucleus), at a lecture at the Royal Institution in London.
J. J. Thomson ↗1961
K-19, the first Soviet nuclear submarine equipped with nuclear missiles, is commissioned.
Soviet submarine K-19 ↗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.
General-audience astronomy and spaceflight — none of it a textbook.
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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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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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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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