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August 20 in spaceflight

Wikipedia records 4 spaceflight and astronomy events on August 20. Below are the pictures NASA published on August 20 in 6 different years — each one taken or released on this exact date.

Launches

NO DATA

0MISSIONS

The launch archive is still being mirrored, so this day has no launches listed yet.

Recorded events

IN THE RECORD

4ENTRIES

Spaceflight and astronomy entries from Wikipedia's record of this date, oldest first — from 1909 onward.

Pictures from this date

PUBLISHED

6IMAGES

NASA's Astronomy Picture of the Day for August 20, one per year. Some are public domain and some belong to the photographer — each says which.

Published on August 20

NASA’s Astronomy Picture of the Day, for this calendar date in each of the last several years.

The Elephant's Trunk in Cepheus

2026

The Elephant's Trunk in Cepheus

Like an illustration in a galactic Just So Story, the Elephant's Trunk Nebula winds through the emission region and young star cluster complex IC 1396, in the high and far off constellation of Cepheus. Also known as vdB 142, this cosmic elephant's trunk is over 20 light-years long. The detailed telescopic view features the bright swept-back ridges and pockets of cool interstellar dust and gas that abound in the region. But the dark, tendril-shaped clouds contain the raw material for star formation and hide protostars within. Nearly 3,000 light-years distant, the relatively faint IC 1396 complex covers a large region on the sky, spanning over 5 degrees. Top to bottom this proboscidean-like rendition reaches across an almost 1 degree wide field of view, though. That's a little less than the angular size of 2 full moons.

© Eddie Sgarbossa — used with the credit NASA publishes

Perseid Meteors from Durdle Door

2025

Perseid Meteors from Durdle Door

What are those curved arcs in the sky? Meteors -- specifically, meteors from this year's Perseid meteor shower. Over the past few weeks, after the sky darkened, many images of Perseid meteors were captured separately and merged into a single frame, taken earlier. Although the meteors all traveled on straight paths, these paths appear slightly curved by the wide-angle lens of the capturing camera. The meteor streaks can all be traced back to a single point on the sky called the radiant, here just off the top of the frame in the constellation of Perseus. The same camera took a deep image of the background sky that brought up the central band of our Milky Way galaxy running nearly vertically through the featured image's center. The limestone arch in the foreground in Dorset, England is known as Durdle Door, a name thought to survive from a thousand years ago.

© Josh Dury — used with the credit NASA publishes

Supermoon Beyond the Temple of Poseidon

2024

Supermoon Beyond the Temple of Poseidon

A supermoon occurred yesterday. And tonight's moon should also look impressive. Supermoons appear slightly larger and brighter than most full moons because they reach their full phase when slightly nearer to the Earth -- closer than 90 percent of all full moons. This supermoon was also a blue moon given the definition that it is the third of four full moons occurring during a single season. Blue moons are not usually blue, and a different definition holds that a blue moon is the second full moon that occurs during a single month. The featured image captured the blue supermoon right near its peak size yesterday as it was rising beyond the Temple of Poseidon in Greece. This supermoon is particularly unusual in that it is the first of four successive supermoons, the next three occurring in September, October, and November.

NASA · public domain

A Roll Cloud Over Wisconsin

2023

A Roll Cloud Over Wisconsin

What kind of cloud is this? A type of arcus cloud called a roll cloud. These rare long clouds may form near advancing cold fronts. In particular, a downdraft from an advancing storm front can cause moist warm air to rise, cool below its dew point, and so form a cloud. When this happens uniformly along an extended front, a roll cloud may form. Roll clouds may actually have air circulating along the long horizontal axis of the cloud. A roll cloud is not thought to be able to morph into a tornado. Unlike a similar shelf cloud, a roll cloud is completely detached from their parent cumulonimbus cloud. Pictured here, a roll cloud extends far into the distance as a storm approaches in 2007 in Racine, Wisconsin, USA.

NASA · public domain

Stardust and Comet Tails

2022

Stardust and Comet Tails

Heading for its closest approach to the Sun, or perihelion, on December 19 comet C/2017 K2 (PanSTARRS) remains a sight for telescopic observers as it sweeps through planet Earth's skies in the constellation Scorpius. The comet currently sports a greenish coma, long whitish dust tail, and short ion tail in this deep image from August 18. The 2x3 degree wide field of view includes part of the dusty nebula IC 4592 reflecting blue starlight. Also known as the Blue Horsehead Nebula, IC 4592 is about 400 light-years distant while the comet is just under 17 light-minutes away. First spotted at a distance well beyond the orbit of Saturn C/2017 K2 is on its maiden voyage to the inner solar system, a pristine visitor from the remote Oort cloud.

© C/2017 K2 (PanSTARRS) remains a sight — used with the credit NASA publishes

Three Perseid Nights

2021

Three Perseid Nights

Frames from a camera that spent three moonless nights under the stars create this composite night skyscape. They were recorded during August 11-13 while planet Earth was sweeping through the dusty trail of comet Swift-Tuttle. One long exposure, untracked for the foreground, and the many star tracking captures of Perseid shower meteors were taken from the village of Magyaregres, Hungary. Each aligned against the background stars, the meteor trails all point back to the annual shower's radiant in the constellation Perseus heroically standing above this rural horizon. Of course the comet dust particles are traveling along trajectories parallel to each other. The radiant effect is due only to perspective, as the parallel tracks appear to converge in the distance against the starry sky. Notable APOD Image Submissions: Perseid Meteor Shower 2021

© Balint Lengyel — used with the credit NASA publishes

What happened on August 20

  1. 1909

    Pluto (pictured) was photographed for the first time at the Yerkes Observatory in Williams Bay, Wisconsin, U.S., 21 years before it was officially discovered by Clyde Tombaugh.

    Pluto
  2. 1955

    Battle of Philippeville: In Algeria, a force of Berbers from the Atlas Mountains region of Algeria raid two rural settlements and kill 77 French nationals.

    Philippeville massacre
  3. 1975

    Viking program: NASA launches the Viking 1 planetary probe toward Mars.

    Viking program

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.

FIELD KIT / LIBRARY

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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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