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.

2022 October 1
See Explanation. Clicking on the picture will download
the highest resolution version available.

Lunation Matrix
Image Credit & Copyright: Tunc Tezel (TWAN)

Explanation: Observe the Moon every night and you'll see its visible sunlit portion gradually change. In phases progressing from New Moon to Full Moon to New Moon again, a lunar cycle or lunation is completed in about 29.5 days. Top left to bottom right, this 7x4 matrix of telescopic images captures the range of lunar phases for 28 consecutive nights, from the evening of July 29 to the morning of August 26, following an almost complete lunation. No image was taken 24 hours or so just after and just before New Moon, when the lunar phase is at best a narrow crescent, close to the Sun and really hard to see. Finding mostly clear Mediterranean skies required an occasional road trip to complete this lunar cycle project, imaging in early evening for the first half and late evening and early morning for the second half of the lunation. Since all the images are registered at the same scale you can use this matrix to track the change in the Moon's apparent size during the single lunation. For extra credit, find the lunar phase that occurred closest to perigee.

Tonight: International Observe the Moon Night
Tomorrow's picture: cosmic cannon < | 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.
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& Michigan Tech. U.


Page 2

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.

2022 October 2
The featured illustration a supernova remnant with a line extending to the lower right that is the trail of a neutron star.
Please see the explanation for more detailed information.

Supernova Cannon Expels Pulsar J0002
Image Credit: F. Schinzel et al. (NRAO, NSF), Canadian Galactic Plane Survey (DRAO), NASA (IRAS);
Composition: Jayanne English (U. Manitoba)

What would it take to shoot out a neutron star? There is a big bang. About 10,000 years ago, a massive star was destroyed by a supernova that created a pulsar and flung it out into the sky. Einstein@Home was used to discover the pulsar, which spins 8.7 times a second. The pulsar J0002+6216 is traveling over 1,000 kilometers per second and is fast enough to leave our galaxy. The trail of the pulsar extends to the left of the supernova remnant. There is a combination of radio images from the VLA and DRAO radio observatories as well as data from NASA's IRAS observatory. It's well known that supernovas can act as cannons, but what's not known is how they do it.

Tomorrow's picture: flyby europa

< | 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.