Catching Jupiter’s Great Red Spot

With Jupiter high in the sky in Gemini, and close to opposition (back on Jan 10), this is a good time attempt some β€œclose-up” observing of the great planet.

Jupiter’s rotation period is about 9h 55m, though the different bands and zones have slightly different values. The most famous feature is the Great Red Spot (GRS). When it first was observed is a little unclear: definite observations go back to 1831, though mentions of a Jupiter β€œspot” go back to 1664, though some of them might’ve been shadow transits of the Galilean moons, or a different β€œspot” altogether.

The spot we see now is an enormous cyclone whose top extends past the bands and zones crossing the planet. It’s about the size of the Earth though it has shrunk over the last decades, and – sadly – dimmed but it’s still within reach of moderate telescopes.

For February, here are the transit times (EST) during evening hours. The β€œwindow of opportunity” is ~45 min on either side of these times:

Date/ESTDate/ESTDate/EST
Feb 5: 6:31 PMFeb 14: 8:55 PMFeb 24: 7:12 PM
Feb 7: 8:09 PMFeb 16: 10:34 PMFeb 26: 8:50 PM
Feb 9: 9:47 PMFeb 19: 8:03 PMMar 3: 7:58 PM
Feb 11: 11:26 PMFeb 21: 9:42 PM

Or the GRS and Moon Shadow

If you can brave the cold into the late evening/early morning there are also opportunities to see the Great Red Spot along with a shadow transit of one of Jupiter’s moons! opportunities this month:

Date / ESTMoon
Feb 4: 11:15 PMIo
Feb 16: 3:00 AMEuropa
Feb 18: 11:35 PMGanymede
Feb 26: 1:24 AMGanymede

Mercury in the Evening

Mercury after twilight, mid-April

2026 isn’t the best year for catching Mercury, but the best chance might come on the evenings surrounding Feb 19th and 20th. While only 15Β° from the Sun, it sets right at the end of twilight, around 7 PM (the Sun sets at 5:30). The thin crescent Moon might help: it’ll be higher in the sky on the night of the 20th and β€œpoints” to Mercury’s position. (The night before the Moon will be just below the planet but with a very thin crescent!) Saturn is there too, but will be a magnitude fainter than Mercury.

This Month’s Image

Bob Donahue, NBAS
Messier 46 in Puppis is a two-fer!

Cataloged as an open cluster, it’s typically overshadowed by other more-famous winter objects, but it’s an easy find in NW Puppis (and next to neighboring cluster M 47). It’s bright enough to be a easy target for small telescopes (even binoculars), but the cluster (5000 ly away) is being β€œphotobombed” by a closer (1370 ly) planetary nebula, NGC 2438, that started forming 8.5 kyr ago when its parent star shed its outer atmosphere leaving a hot core heating the shed gases and creating the smoky ring of the nebula. As it expands and the stellar remnant cools, it will slowly fade away.