Today in the History of Astronomy | Page 2 of 30 | Astronomy.com

A broad, S-shaped spiral formation with a brightly glowing yellow-white core rests tilted at the center of a dark, starry sky. Two faint, hazy blue arms curve outward from the center, surrounded by smaller, scattered pinpricks of white light. Near the lower right curve of the outer arm, two small red lines form a right-angle marker pointing to a single bright white star-like dot.

Today in the History of Astronomy

Sept. 20, 2016: Spotting a supernova shock breakout

An aerial view shows a massive, white dish structure tilted upward in the center, supported by a dense lattice of metal scaffolding. A tall white support arm extends high above the dish toward the top frame. The structure sits on a wide, cleared grey clearing surrounded by green grassy areas and a thick border of dark green forest.

Today in the History of Astronomy

Sept. 19, 1959: A SETI kickstart

A bright greenish-yellow streaks vertically down the center of a dark night sky filled with tiny stars, fanning out softly into a faint, curved white tail near the top. In the lower-right corner, a dark, silhouetted horizon is bordered by a intense, glowing red and orange sky band. The bright streak and colorful horizon contrast sharply against the surrounding deep black space.

Today in the History of Astronomy

Sept. 18, 1965: Discovery of Comet Ikeya-Seki

A black-and-white photograph shows a crescent moon-like body positioned on the right side of the frame against a solid black space background. Strong side lighting illuminates its heavily cratered grey surface, featuring a prominent, large circular crater with a bright raised rim near the center edge. The left half of the spherical body vanishes completely into deep shadow, creating high visual contrast.

Today in the History of Astronomy

Sept. 17, 1789: William Herschel discovers Mimas

A sepia-toned bust portrait features a man with wire-rimmed spectacles, thin hair, a mustache, and a goatee, looking directly forward. He wears a high-collared military tunic adorned with light-colored epaulets on both shoulders and small medals pinned to his left chest pocket. The subject is evenly illuminated against a smooth, dark, monochromatic backdrop.

Today in the History of Astronomy

Sept. 16, 1925: Death of Alexander Friedmann

A pale yellow, smoothly textured sphere fills the bottom half of the frame, slanting downward to the right. A thin, vivid blue outline traces its curved edge against a solid black space background. A tiny, dim grey crescent moon peeks out from directly behind the blue horizon near the center.

Robotic Spaceflight, Today in the History of Astronomy

Sept. 15, 2017, Cassini’s Grand Finale

Telescopes and Equipment, Today in the History of Astronomy

Sept. 14, 1915: The birth of John Dobson

An illustration shows a boxy, gold-foil-wrapped spacecraft with a large black dish antenna on the left, positioned in front of a glowing, fiery sphere on the right against a solid black space background. The central sun-like orb ranges in color from dark, swirling reddish-browns to intense, bright yellow flare-like bursts around its edges. Several thin, metallic booms and antenna rods extend outward diagonally from the main body of the satellite, creating strong geometric contrast with the soft, fiery texture behind it.

Robotic Spaceflight, Today in the History of Astronomy

Sept. 13, 1994: Ulysses at the Sun’s south pole

A metallic grey sphere made of interlocking pentagonal and hexagonal tiles sits centrally against a bright, plain white background. Each brushed-metal tile is engraved with Cyrillic text, numerals, and small crest emblems, resembling a soccer ball structure. Overhead display lighting creates soft reflections on the upper hemisphere and subtle shadows along the lower curves.

Robotic Spaceflight, Today in the History of Astronomy

Sept. 12, 1959: Luna 2 launches

An illustration shows a cylindrical spacecraft floating centrally against a dark, painted background of deep purple and blue space speckled with white stars. The main metallic body features blue solar panels along its sides and a bright teal circular end, with numerous thin antennas and booms extending outward in all directions like spiky spokes. Even, bright lighting highlights the satellite's intricate shape against the dark starfield backdrop.

Robotic Spaceflight, Today in the History of Astronomy

Sept. 11, 1985: The ICE probe encounters Comet Giacobini-Zinner

A rectangular postage stamp with a red perforated border features an illustrated portrait of a man in a white spacesuit filling the right foreground. To the left, two connected grey spacecraft with solar panels extend diagonally above a blue-and-white view of Earth against a dark starry sky. Bold lettering, numerals, and small colored flags frame the upper corners and right side under even, bright lighting.

Human Spaceflight, Today in the History of Astronomy

Sept. 10, 1933: The birth of Yevgeny Khrunov

A small, blurry, strawberry-shaped blob glowing in warm orange and red tones sits centered within a dark square inset. Two faint, yellowish points of brightness stand out along its right edge, contrasting against the muted red body. The entire square frame is isolated against a solid black background, giving the object high contrast.

Today in the History of Astronomy

Sept. 9, 1892: Edward Emerson Barnard sees Amalthea