Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2023 December 17
Two people are pictured from the back looking at a dark
star-filled sky. The sky is also filled with numerous streaks
caused by meteors from the Geminids meteor shower.
Please see the explanation for more detailed information.

Geminids over China's Nianhu Lake
Image Credit & Copyright: Hongyang Luo

Explanation: Where are all of these meteors coming from? In terms of direction on the sky, the pointed answer is the constellation of Gemini. That is why the major meteor shower in December is known as the Geminids -- because shower meteors all appear to come from a radiant toward Gemini. Three dimensionally, however, sand-sized debris expelled from the unusual asteroid 3200 Phaethon follows a well-defined orbit about our Sun, and the part of the orbit that approaches Earth is superposed in front of the constellation of Gemini. Therefore, when Earth crosses this orbit, the radiant point of falling debris appears in Gemini. Featured here is a composite of many images taken a few days ago through dark skies from Nianhu Lake in China. Over 100 bright meteor streaks from the Geminids meteor shower are visible.

APOD Year in Review (2023): RJN's Night Sky Network Lecture
Tomorrow's picture: the same color


< | Archive | Submissions | Index | Search | Calendar | RSS | Education | About APOD | Discuss | >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
NASA Official: Phillip Newman Specific rights apply.
NASA Web Privacy Policy and Important Notices
A service of: ASD at NASA / GSFC,
NASA Science Activation
& Michigan Tech. U.