NASA rover reboots twice over Easter weekend Options

[Deimos]

NASA rover resurrected twice over Easter weekend

Moderator adding: the JPL press release is here.

[fredk]

A few details on the Spirit anomalies in the new update.

[ilbasso]

A few details on the Spirit anomalies in the new update.

Can someone please explain in clearer English this extract from the above-referenced update: "no sol number for Spirit corresponded to April 2, 2009, using the criterion of the date in Los Angeles at local solar noon on Mars"?

Thanks,
Jonathan

[tfisher]

Can someone please explain in clearer English this extract from the above-referenced update: "no sol number for Spirit corresponded to April 2, 2009, using the criterion of the date in Los Angeles at local solar noon on Mars"?

A solar day on mars is a bit longer than a day on earth -- about 24 hours 39 minutes (per wikipedia -- http://en.wikipedia.org/wiki/Timekeeping_on_Mars). When they convert Martian sols to Earth dates, they are saying they take the date as the date in Los Angeles at the time of solar noon for the rover. With the slightly longer Martian day, it must have worked out that noon on sol 1865 landed just before midnight on April 1st while noon on sol 1866 landed in the wee hours of the morning on April 3, twenty-four and a half hours later (or so).

--Travi

[centsworth_II]

A solar day on mars is a bit longer than a day on earth -- about 24 hours 39 minutes...

Since an Earth day has 1440 minutes and a Mars day is 39 minutes longer than an Earth day, there are about 38 Earth days for every 37 Mars sols.* So it makes mathematical sense that when corresponding Earth days to Martian sols, a day needs to be "lost" every 37 sols.

*1440/39 = 36.92 (That's the extent of my math prowess, no orbital calculations for me! )