The Half-Astrophysicist Blog

Can You Spy Jupiter During the Day?

Other than the Sun and the Moon, it is challenging to see astronomical objects during the day. Venus is commonly seen during the day (and I will blog about it soon as it is becoming well positioned for daytime sightings). Jupiter is the other object that can occasionally be glimpsed during the day, but it is very challenging.

Fortunately, the Moon makes a close pass near Jupiter on January 2nd giving you a bit of help in this challenging observation. I recommend using a program such as Stellarium to make a finder chart for your particular location and time. Your best bet is late afternoon when the Moon and Jupiter have risen high enough in the east to make them easier to see. Here is a chart for Tucson at about 4pm tomorrow (the Moon moves about one Moon diameter per hour, so if you are observing several hours earlier or later, you might want to make a chart for yourself!)

Start by finding the Moon. You need to focus your eyes at infinity to have any chance of seeing Jupiter and the Moon is close enough to infinity that you can use it. Slowly scan toward the Jupiter. You have to look DIRECTLY at Jupiter to see it (that is Jupiter must be focused on the fovea, the center of your retina where you have the most sensitive vision) and it will pop into view. If you are off just a little bit, you won’t see it so this observation takes some patience! Some people find it is easier to wait until the Sun is almost going down, but I like the challenge of the fully illuminated sky!

It is much easier to take a pic of Jupiter during the day. Zoom in on the Moon (but not too far) and take a short exposure. Examine it closely on your computer screen to find Jupiter.

I have seen Jupiter during the day several times. It takes practice but is possible. If you are successful, you will join a fairly small and select group who have achieved this challenging observation.


January 2, 2012 - Posted by | Daytime Astronomy, Observing, Solar System

1 Comment »

  1. The path of Jupiter against the background stars of Pisces, Aries, Taurus and Gemini from May 2011 to July 2014, with positions marked on the 1s of each month. Periods of invisibility (i.e. when the planet is too close to the Sun, or passes behind it) are indicated by a dashed line; hence the planet becomes lost from view (in the evening sky) in late April 2012 and becomes visible again (in the morning sky) in early June 2012. The chart shows the changing shape of a planet’s apparent looping formation as it moves through the zodiac. Being positioned South of the ecliptic during 2011-12, Jupiter describes a Southwards-facing loop in Aries, then a hybrid formation (half loop, half zig-zag) a year later in Taurus. As the planet crosses the ecliptic (heading Northwards) in Gemini in 2013-14 it describes a zig-zag formation. The star map applies to observers in the Northern hemisphere (i.e. North is up); for the Southern hemisphere view, click here . The faintest stars on the map have an apparent magnitude of about 4.8. Printer-friendly versions of this chart are available for Northern and Southern hemisphere views. Astronomical co-ordinates of Right Ascension (longitude, measured Eastwards in hrs:mins from the First Point of Aries) and Declination (latitude, measured in degrees North or South of the celestial equator) are marked around the border of the chart. Other interesting objects on the chart which are observable through telescopes and binoculars are discussed in the main text below. Night sky photographs of the region, together with descriptions of bright stars, stars near Jupiter’s path and multiple stars are detailed here , whilst star clusters, nebulae and galaxies are detailed here .

    Comment by dieta | January 14, 2012 | Reply

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