Tonight and for the next few nights, as seen from around the world, the waning gibbous moon and Jupiter are close together and the brightest objects in your sky from late evening on. They are beautiful! Look outside late, say around midnight, on the evenings of December 10, 11 or 12 2014. You can’t miss them. They’re the brightest things up there. After the moon and Jupiter climb into the sky in mid- to late evening, they’ll be out for rest of the night. That means if you’re not one for staying up late, you can also look for the moon and Jupiter in the morning sky. These two worlds will be highest up for the night during the predawn hours and still high up at dawn.
Recommended almanacs help you find rising times of moon and Jupiter into your sky
Jupiter just began its retrograde motion on December 9. That means the best time of year to see this giant planet is upon us. Start watching it this week, and enjoy it for months to come. Jupiter will be at its absolute best – with Earth moving between this outer planet and the sun – in February, 2015.
A modest low-powered telescope easily shows you the four major moons of Jupiter. You can also glimpse the moons with ordinary binoculars. In their outward order from Jupiter these moons are Io, Europa, Ganymede and Callisto.
On the morning of December 11, 2014, as seen from North America, Ganymede and Europa will appear on one side of Jupiter while Io and Callisto will appear on the other. These moons will look like pinpricks of light on nearly the same plane.
EarthSky lunar calendars make great gifts for astronomy-minded friends and family.
Earth’s moon gives you a good idea of the sizes of Jupiter’s four major moons. Our moon is a bit smaller than Io but a bit larger than Europa. Ganymede, the largest moon in the solar system, and Callisto, the third-largest, have diameters that are about 1.5 times greater than that of our moon.
Like our moon, Jupiter’s moons always have one side facing Jupiter and the other side facing away their parent planet. That’s because these moons rotate on their axes and orbit their parent planet in the same amount of time. This is known as synchronous rotation.
Unlike our moon, Jupiter’s moons orbit Jupiter above Jupiter’s equator. In other words, the orbital plane of these moons coincides with the plane of Jupiter’s equator.
On the other hand, our moon’s orbital plane is inclined to the plane of the Earth’s equator, with the moon’s orbital inclination varying from 18.5o to 28.5o and back to 18.5o over a cycle of 18.6 years.
Bottom line: Be sure to look outside late at night on December 10, 2014 – or early in the morning on December 11 – for the beautiful moon and Jupiter. Also in this post .. a chart and info on how to identify Jupiter’s moons Thursday morning.
How astronomers use Jupiter’s moons to determine Jupiter’s mass
Donate: Your support means the world to us
from EarthSky http://ift.tt/1yOFQLq
Tonight and for the next few nights, as seen from around the world, the waning gibbous moon and Jupiter are close together and the brightest objects in your sky from late evening on. They are beautiful! Look outside late, say around midnight, on the evenings of December 10, 11 or 12 2014. You can’t miss them. They’re the brightest things up there. After the moon and Jupiter climb into the sky in mid- to late evening, they’ll be out for rest of the night. That means if you’re not one for staying up late, you can also look for the moon and Jupiter in the morning sky. These two worlds will be highest up for the night during the predawn hours and still high up at dawn.
Recommended almanacs help you find rising times of moon and Jupiter into your sky
Jupiter just began its retrograde motion on December 9. That means the best time of year to see this giant planet is upon us. Start watching it this week, and enjoy it for months to come. Jupiter will be at its absolute best – with Earth moving between this outer planet and the sun – in February, 2015.
A modest low-powered telescope easily shows you the four major moons of Jupiter. You can also glimpse the moons with ordinary binoculars. In their outward order from Jupiter these moons are Io, Europa, Ganymede and Callisto.
On the morning of December 11, 2014, as seen from North America, Ganymede and Europa will appear on one side of Jupiter while Io and Callisto will appear on the other. These moons will look like pinpricks of light on nearly the same plane.
EarthSky lunar calendars make great gifts for astronomy-minded friends and family.
Earth’s moon gives you a good idea of the sizes of Jupiter’s four major moons. Our moon is a bit smaller than Io but a bit larger than Europa. Ganymede, the largest moon in the solar system, and Callisto, the third-largest, have diameters that are about 1.5 times greater than that of our moon.
Like our moon, Jupiter’s moons always have one side facing Jupiter and the other side facing away their parent planet. That’s because these moons rotate on their axes and orbit their parent planet in the same amount of time. This is known as synchronous rotation.
Unlike our moon, Jupiter’s moons orbit Jupiter above Jupiter’s equator. In other words, the orbital plane of these moons coincides with the plane of Jupiter’s equator.
On the other hand, our moon’s orbital plane is inclined to the plane of the Earth’s equator, with the moon’s orbital inclination varying from 18.5o to 28.5o and back to 18.5o over a cycle of 18.6 years.
Bottom line: Be sure to look outside late at night on December 10, 2014 – or early in the morning on December 11 – for the beautiful moon and Jupiter. Also in this post .. a chart and info on how to identify Jupiter’s moons Thursday morning.
How astronomers use Jupiter’s moons to determine Jupiter’s mass
Donate: Your support means the world to us
from EarthSky http://ift.tt/1yOFQLq
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