Category Archives: Whats Up

All the Whats Up in the Nights Sky events

Whats Up in the Nights Sky March 23rd 2015

Venus shines well to the Moon’s lower right this evening.

Venus is brightest point of light at dusk. The second-brightest is Jupiter, much higher in the southeast. Look to the right of Jupiter by two or three fists at arm’s length for Procyon; look the same distance lower right from Procyon, and there’s the evening’s third-brightest point, Sirius.

Whats Up in the Nights Sky March 22nd 2015

Crescent Moon and Venus. Look west in twilight for the waxing crescent now posing with Venus, as shown here. At the times of twilight for North America, Venus is 3° or 4° to the Moon’s right. Although they look close together, Venus is currently 520 times farther away.

What’s Up in the Nights Sky March 21st 2015

In twilight, look west well below Venus for a very thin waxing crescent Moon close to Mars, as shown here. The Moon is just one day old following yesterday’s solar eclipse. We see the Moon’s night side (dimly Earthlit), and just a little of the sunlit side around the edge, because the Moon is nearly along our line of sight to the Sun. Faraway Mars shows us mostly its day side, because it’s nearly on the same line of sight on the far side of the Sun. Tomorrow evening the Moon will be beautifully paired with Venus; make a note to look.

What’s Up in the Nights Sky March 20th 2015

The Sun undergoes a total eclipse for parts of the North Atlantic and Arctic Oceans. The partial phases sweep across a much larger area: all of Europe, North Africa, and central Asia. Maps and explanations (particularly for the UK). More maps and detailed local timetables are at Fred Espenak’s EclipseWise site.

As dusk turns to night, spot Venus still in the west. To its upper right by about a fist at arm’s length, look for 2.0-magnitude Hamal, the brightest star of Aries. Farther to Venus’s upper left or left, look for 2.5-magnitude Menkar, Alpha Ceti. Spring begins in the Northern Hemisphere at the equinox, 6:45 p.m. EDT (3:45 p.m. PDT). This is when the Sun crosses the equator heading north for the season.

The word “equinox” comes from night and day supposedly being equal on this date, but that’s just wrong. It would be true if Earth had no atmosphere and the Sun were a point rather than a disk. But with an atmosphere, daylight continues long after the moment of sunset. Second, sunrise and sunset are counted not from when the Sun’s center is on the true horizon, but when its top edge is on the horizon; this adds a couple minutes to daytime. And third, atmospheric refraction at the horizon elevates the Sun by about its own apparent diameter, adding a few more minutes to official daytime.