Autumnal equinox on September 23
Photo: Joe Orman
We have an equinox once every six months, or twice a year.
And the next time will be Sunday morning – September 23, 2007 – at 9:51 a.m. Universal Time. On the day of any equinox, the sun rises due east and sets due west, as seen from all over the world. The length of the day is the same everywhere, with everyone worldwide receiving 12 hours of daylight and 12 hours of night.
At an equinox, neither Earth’s north pole nor its south pole is tilting away from or toward the sun. Both poles are more or less evenly illuminated. At the instant of Sunday’s equinox, the sun will stand straight overhead at noon as seen from Earth’s equator. This September equinox marks the beginning of northern hemisphere autumn and southern hemisphere spring.
After Sunday’s equinox, as Earth pursues its yearly orbit around the sun, our world’s southern axis will slowly shift into a tilt toward the sun, while the Earth’s northern axis will begin tilting away. By the end of the month, the sun will rise and set noticeably south of due east and west. And the sun will continue to rise and set farther south daily until the December 22 solstice.
To celebrate this equinox, watch for Venus before sunrise tomorrow – at its brightest until May of 2009.
What was the large object in the sky near the moon tonight around sunset? It was visible in Santa Fe, New Mexico, about 7:00 p.m. and appeared larger than a planet.
Julee,
I’m presuming you are referring to nightfall or early evening of Saturday, Sept. 22. On the nights of Sept. 22 & 23, the moon resides in front of the constellation Capricorn, which has no bright stars or any planet that is visible to the unaided eye. How far was this object from the moon? If it shone close to your southeast horizon, but a fairly good ways beneath the moon, it could have been the star Fomalhaut.
Bruce
It appeared much bigger to the eye than a star. I saw in the paper that there was a weather balloon visible! That must have been it.
Julee,
How cool! Thanks for letting us know!
Bruce