The sky on
your birthday.
Ninety Gravitational Wave Spectrograms and Counting
Every time two massive black holes collide, they send out a loud chirping sound in gravitational waves. Humanity has only been able to detect these chirps for seven years, but we have already heard about 90 of them. This image shows spectrograms, plots of gravitational wave frequency versus time, detected by LIGO, VIRGO, and KAGRA.
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Released on your day
Space pictures released on your month and day in other years, or a few days either side. Each one is sharp enough to print as a poster.
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The Sun on your day The Sun on 7 December 2021 See it as a poster -
The Earth on your day The Earth on 7 December 2021 · Sahara, Algeria See it as a poster -
Released on 7 December 2011 Wide field view of the unusual double star SS Leporis See it as a poster -
Released on 7 December 2020 The Stellar Forge See it as a poster -
Released on 7 December 2015 Galactic politics See it as a poster -
Released on 7 December 2010 The Impressive Rays of Hokusai See it as a poster -
Released on 7 December 2022 Flight Day 22: Orion Looks Back at the Moon See it as a poster
In tropical astrology, 7 DEC 2021 falls under Sagittarius (♐). The sign's window runs from 11-22 through 12-21. Sagittarius points straight at the center of the Milky Way, our galaxy's brightest region. The Sun was crossing this region of the sky on 7 DEC 2021.
Questions about December 7, 2021
What space photo was released on December 7, 2021?
NASA's Astronomy Picture of the Day for December 7, 2021 was "Ninety Gravitational Wave Spectrograms and Counting". It's the card at the top of this page.
What was the Moon's phase on December 7, 2021?
A waxing crescent moon, about 10% lit.
What day of the week was December 7, 2021?
December 7, 2021 was a Tuesday, day 341 of the 365 days in 2021.
What did the Sun and the Earth look like on December 7, 2021?
NASA's Solar Dynamics Observatory photographed the Sun that day, and NASA's Terra satellite photographed the whole Earth. Both are on this page, next to the card.
Is it free?
Yes. Seeing, sharing and downloading the card is free, and there's no account to make.