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back to article Skygazers prepare for 'blood Moon' caused by Earth eclipse

North American night owls will be in prime position to catch their best view of a lunar eclipse at around 1am EDT Tuesday as our natural satellite is overshadowed by Earth. The Earth's shadow will start to cover the Moon's surface at 12:54am EDT and the cover the lunar surface completely between 3:07am and 4:25am, causing a …

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  1. Christoph

    Why is this a problem?

    Why is the probe endangered by an eclipse? It must be coping with going into the moon's shadow every orbit.

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    1. Thecowking
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      Re: Why is this a problem?

      Not necessarily , it could be orbiting at an angle, so the time it spends in shadow could be much lower, or possibly never in shadow at all.

      If it's in an elliptical orbit it can skim close to the moon on the day side and then swing far above the moon's shadow on the night side too.

      So there's a couple of ways it can not experience this in normal operation.

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      1. Christoph
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        Re: Why is this a problem?

        Except that is isn't in an elliptical orbit - it's in a very low almost circular orbit. Check the NASA site - there's nothing about it 'orbiting at an angle'.

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      2. Alexandicity
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        Re: Why is this a problem?

        Not wrong; there are indeed orbits like you say to keep it in the sun. LADEE, however, is in a very low (50km!), circular and equatorial orbit, so it spends just under 50% of its time in the Moon's shadow - about an hour each time around.

        Problem is that the batteries are designed with the assumption that they will get to charge every orbit. With a 2 (?) hour period where the moon will be much darker than usual, there's going to be at least one "charging period" that the satellite won't have the light it expects. This means the battery won't charge enough and, before it gets full sunlight again the battery will be drained "dangerously" low.

        That said, normally they'd turn off many systems not necessary for the satellite's immediate survival to save power in such a case. Seems surprising to me that they can't keep it warm and alive with certainty if they turned off the science payload, for example...

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        1. Anonymous Coward
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          Anonymous Coward

          Re: Why is this a problem?

          If I've read the site correctly, it has an orbital period of 113 minutes. Assuming it's in sunlight for about 50% of that time, it needs charging about as frequently as an iPhone 5c.

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        2. Anonymous Coward
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          Anonymous Coward

          Re: Why is this a problem?

          It's too bad that this lunar eclipses couldn't have been predicted.

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  2. Tom 13

    I realize we're a continent away and not your primary focus, but...

    North American night owls will be in prime position to catch their best view of a lunar eclipse at around 1am EDT Tuesday as our natural satellite is overshadowed by Earth.

    Don't you think you should check the weather forecast before you post tripe like that? Especially when listing Eastern Daylight Time? We were pretty much buried in clouds. Which if posts here are to be believed, sounds pretty much like the typical situation in Old Blighty.

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