火星的日食：火卫一凌日

2022年5月9日

A Martian Eclipse: Phobos Crosses the Sun
Video Credit: NASA, JPL-Caltech, ASU MSSS, SSI

Explanation: What’s that passing in front of the Sun? It looks like a moon, but it can’t be Earth’s Moon, because it isn’t round. It’s the Martian moon Phobos. The featured video was taken from the surface of Mars a month ago by the Perseverance rover. Phobos, at 11.5 kilometers across, is 150 times smaller than Luna (our moon) in diameter, but also 50 times closer to its parent planet. In fact, Phobos is so close to Mars that it is expected to break up and crash into Mars within the next 50 million years. In the near term, the low orbit of Phobos results in more rapid solar eclipses than seen from Earth. The featured video is shown in real time — the transit really took about 40 seconds,as shown. The videographer — the robotic rover Perseverance (Percy) — continues to explore Jezero Crater on Mars, searching not only for clues to the watery history of the now dry world, but evidence of ancient microbial life.

New Social Mirror: APOD now available on mastodon

Tomorrow’s picture: giant space paw

火星的日食：火卫一凌日
影片提供: NASA, JPL-Caltech, ASU MSSS, SSI

说明: 从太阳前方掠过的天体是什么？它乍看像颗卫星，不过肯定不是月亮，因为它没浑圆的轮廓。它其实是火星的火卫一。这部主题影片是在一个月之前，由毅力号火星车摄于火星的表面。宽约11.5公里的火卫一，直径只有月亮的150分之1，但与母行星的间距却要比月亮近50倍。由于火卫一是如此邻近火星，以至于在接下来的5千万年之内，火卫一预期会土崩瓦解并撞进火星。较近期来说，火卫一密近的低轨道所造成的日食景观，进程要比在地球所见到的类似事件快速。这部实时主题影片，所呈现的凌日过程约历时40秒。影片的摄像者毅力号火星车（Percy 波西）持续探索火星的耶杰罗坑，不仅要寻目前已干涸的火星之水世界前生历史，也要寻找古微生物生命曾存在的证据。

新社交镜像: APOD现已在mastodon上发布

明日的图片: giant space paw