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Not necessarily "outdated" as much as simply exactly what the ever-articulate (see also) Brandon Rhodes has written: "X days from the epoch" (unsigned, could be either direction) because TLEs are sometimes post-dated to the future by as much as several weeks, and PyEphem may feel that it is too early to use that TLE as well as too late.

note: pyephem (depreciated, "old-and-busted" (not really)) and skyfield ("new hotness") are supported by the same person.

Don't believe me? Then see the excellent answers to the question Can the TLE epoch be listed as in the future? How?

See @Tristan's excellent and thorough answer to the question Is SGP4 propagation necessarily more accurate near the epoch chosen for TLE generation?

It also may not be at all that "pyephem may not be up to the task." as much as it's simply recognized that any use of SGP4 (pyephem or otherwise) is known to give increasingly worse results away from epoch. This would be true of anything accepting a TLE because it would be implementing SGP4 (or worse). See all these linked answers for this sites best explanations of this (in my opinion).

Not necessarily "outdated" as much as simply exactly what the ever-articulate (see also) Brandon Rhodes has written: "X days from the epoch" (unsigned, could be either direction) because TLEs are sometimes post-dated to the future by as much as several weeks, and PyEphem may feel that it is too early to use that TLE as well as too late.

note: pyephem (deprecated, "old-and-busted" (not really)) and skyfield ("new hotness") are supported by the same person.

Don't believe me? Then see the excellent answers to the question Can the TLE epoch be listed as in the future? How?

See @Tristan's excellent and thorough answer to the question Is SGP4 propagation necessarily more accurate near the epoch chosen for TLE generation?

It also may not be at all that "pyephem may not be up to the task." as much as it's simply recognized that any use of SGP4 (pyephem or otherwise) is known to give increasingly worse results away from epoch. This would be true of anything accepting a TLE because it would be implementing SGP4 (or worse). See all these linked answers for this sites best explanations of this (in my opinion).

Not necessarily "outdated" as much as simply exactly what the ever-articulate (see also) Brandon Rhodes has written: "X days from the epoch" (unsigned, could be either direction) because TLEs are sometimes post-dated to the future by as much as several weeks, and PyEphem may feel that it is too early to use that TLE as well as too late.

Don't believe me? Then see the excellent answers to the question Can the TLE epoch be listed as in the future? How?

See @Tristan's excellent and thorough answer to the question Is SGP4 propagation necessarily more accurate near the epoch chosen for TLE generation?

It also may not be at all that "pyephem may not be up to the task." as much as it's simply recognized that any use of SGP4 (pyephem or otherwise) is known to give increasingly worse results away from epoch. This would be true of anything accepting a TLE because it would be implementing SGP4 (or worse).

Not necessarily "outdated" as much as simply exactly what the ever-articulate (see also) Brandon Rhodes has written: "X days from the epoch" (unsigned, could be either direction) because TLEs are sometimes post-dated to the future by as much as several weeks, and PyEphem may feel that it is too early to use that TLE as well as too late.

note: pyephem (depreciated, "old-and-busted" (not really)) and skyfield ("new hotness") are supported by the same person.

Don't believe me? Then see the excellent answers to the question Can the TLE epoch be listed as in the future? How?

See @Tristan's excellent and thorough answer to the question Is SGP4 propagation necessarily more accurate near the epoch chosen for TLE generation?

It also may not be at all that "pyephem may not be up to the task." as much as it's simply recognized that any use of SGP4 (pyephem or otherwise) is known to give increasingly worse results away from epoch. This would be true of anything accepting a TLE because it would be implementing SGP4 (or worse). See all these linked answers for this sites best explanations of this (in my opinion).

Not necessarily "outdated" as much as simply exactly what the ever-articulate (see also) Brandon Rhodes has written: X days from the epoch (unsigned, could be either direction) because TLEs are sometimes post-dated to the future by as much as several weeks, and PyEphem may feel that it is too early to use that TLE as well as too late.

Don't believe me? Then see the excellent answers to the question Can the TLE epoch be listed as in the future? How?

See @Tristan's excellent and thorough answer to the question Is SGP4 propagation necessarily more accurate near the epoch chosen for TLE generation?

Not necessarily "outdated" as much as simply exactly what the ever-articulate (see also) Brandon Rhodes has written: "X days from the epoch" (unsigned, could be either direction) because TLEs are sometimes post-dated to the future by as much as several weeks, and PyEphem may feel that it is too early to use that TLE as well as too late.

Don't believe me? Then see the excellent answers to the question Can the TLE epoch be listed as in the future? How?

See @Tristan's excellent and thorough answer to the question Is SGP4 propagation necessarily more accurate near the epoch chosen for TLE generation?

It also may not be at all that "pyephem may not be up to the task." as much as it's simply recognized that any use of SGP4 (pyephem or otherwise) is known to give increasingly worse results away from epoch. This would be true of anything accepting a TLE because it would be implementing SGP4 (or worse).