Jupiter and Venus meet in the morning twilight

Aug

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Early in the mornings this week, the two brightest planets in the sky, Jupiter and Venus, skim past each other so closely that they may look like one single bright planet. They'll be close enough together, in fact, that both will be visible in the same telescopic field of view at moderate magnification.

Start by looking late in the week for the two planets as they saunter towards each other. Venus will initially be the higher, and brighter object. Look below it for Jupiter, dimmer by about 2 full magnitudes. Despite the twilight glow, both of these wanderers in the sky are bright enough that they ought to be visible for quite some time in the increasing twilight before sunrise. Look for your local sunrise time, and and 45 minutes to an hour beforehand, look towards the east-northeast with an unobstructed or very low horizon.

Binoculars can help you spot Venus first as it rises from the thicker column of atmosphere the observer will have to look through as the planet precedes both Jupiter and the Sun. Though normally a brilliant -4.5 magnitude, Venus is about ready to go around the opposite side of the Sun from Earth. So the increased distance, coupled with the similar actual diameter of Earth, means that the planet is a full magnitude fainter than that - and, the additional atmosphere may extinct it even more.

However, even nimble Mercury can be seen at magnitude 0 or 1 as low as five degrees from the horizon, so the brighter Venus can certainly be picked off. On the morning of the 15-th, Venus is ahead of Jupiter by about 3 degrees - approximately two fingers held at arm's length. The dimmer - though much larger and therefore fairly constant brightness - massive gas giant planet gets closer to the sinking Venus by about 3/4 of a degree per day, so that by Monday morning the 18-th, the two are nearly on top of one another!

For more information on this fascinating conjunction, check out the video below, and also look for Mars as it glides under Saturn in the evening sky this week too.

There's a lot more here on Eyes on the Sky. For example, every week on the homepage there is a new astronomy video about observing objects in the night sky. They're only 5 minutes long - why not check out the latest one right now?