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Ephemeris: 10/26/2023 – A closer look at Jupiter’s moon Io
This is Ephemeris for Thursday, October 26th. Today the Sun will be up for 10 hours and 28 minutes, setting at 6:40, and it will rise tomorrow at 8:13. The Moon, 2 days before full, will set at 6:36 tomorrow morning.
My favorite moon of Jupiter has been Io ever since the Voyager 1 spacecraft discovered volcanoes on it. It turns out that Io is the most volcanic body in the solar system and perhaps the least studied of the Galilean moons of Jupiter. Most of the probes that have swung by or orbited Jupiter never got very close to Io, so we never really got a good close look at it. Well, now we are getting that closer look. The Juno spacecraft, which was sent to Jupiter to work out the interior of Jupiter using gravitational effects on its orbit, has now completed its main mission and its orbit has precessed so that now comes close to Io. The Juno spacecraft has a camera, mainly there for the public, which is showing amazing closeups of this moon.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.
Addendum
07/04/2016 – Ephemeris – NASA’s going to light off fireworks at Jupiter tonight
Ephemeris for Independence Day, Monday, July 4th. Today the Sun will be up for 15 hours and 27 minutes, setting at 9:31, and it will rise tomorrow at 6:03. The Moon is new today, and won’t be visible.
There are two astronomical highlights for your Independence Day enjoyment. The first comes at 11:59 this morning (15:59 UT) when the Earth is at its very farthest from the Sun this year. Some 1.7% farther than average. You’re still gonna need your sun screen anyway. Later this evening, a half billion miles from Earth NASA’s Juno spacecraft will fire it’s rocket engine for 35 minutes to begin to decelerate over the north pole of Jupiter to drop into a long elliptical orbit of that planet. NASA TV will begin broadcasting the event at 10:30 p.m. (2:30 UT, July 5) The 35 minute engine burn will start at 11:18 p.m. (3:18 UT, July 5) What we’ll see is a real-time graph of the Doppler signal from the spacecraft as it slows down to drop into orbit of Jupiter.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Juno spacecraft. Credit: NASA.
The Planetary Society’s Emily Lakdawalla has more information on How to watch Juno’s orbit insertion at http://www.planetary.org/blogs/emily-lakdawalla/2016/07011514-how-to-watch-junos-orbit.html.
NASA also has an application in which you can see simulations of Juno’s orbital insertion. It’s called NASA’s Eyes and can be downloaded from http://eyes.nasa.gov/.
02/23/2016 – Ephemeris – The king of the planets is planning to conquer the evening sky. Tonight its enlisting help from the Moon.
Ephemeris for Tuesday, February 23rd. The Sun will rise at 7:31. It’ll be up for 10 hours and 50 minutes, setting at 6:21. The Moon, 1 day past full, will rise at 7:32 this evening.
Rising with the Moon tonight will be the planet Jupiter which will appear to the left of the Moon as they rise, to the upper left of the Moon at 10 p.m. and above the Moon at midnight. NASA’s Juno spacecraft, launched in 2011, is planned to arrive at Jupiter on July 4th this year. No, it’s not a coincidence. It will orbit the planet for nearly two years. It’s the only solar-powered spacecraft that can operate as far from the Sun as Jupiter, which is 5 times farther from the Sun as the Earth, which gets one 5th squared or one twenty-fifth the intensity of sunlight. It has 3 huge solar panels making the spacecraft 66 feet wide. It’s mission is about Jupiter, its internal structure, atmosphere and magnetic and radiation fields.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Jupiter and the Moon animation. Note their change in position relative to each other at 8 p.m., 10 p.m. and midnight. Created using Cartes du Ciel (Sky Chart) and GIMP.
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Closeup of Jupiter and the Moon at 10 p.m., February 23, 2016. The Moon is a whole lot brighter, and Jupiter dimmer than what’s shown here. Created using Stellarium.
The Juno spacecraft. Credit: NASA.
12/08/2015 – Ephemeris – The hard charging Taurus the bull
Ephemeris for Tuesday, December 8th. The Sun will rise at 8:07. It’ll be up for 8 hours and 55 minutes, setting at 5:02. The Moon, 3 days before new, will rise at 6:03 tomorrow morning.
Low in the east at 9 p.m. is the constellation of Orion the giant hunter . Above him is Taurus the bull. His face is a letter V shape of stars lying on its side with the bright orange-red star Aldebaran at the bottom left tip of the V as its angry blood-shot eye. Orion is depicted in the sky facing with club in one hand and a shield in the other the approaching and in some depictions charging Taurus. The V of stars is a star cluster called the Hyades. The Pleiades are in his shoulder above. Taurus in Greek mythology was the guise the god Zeus when he carried off the maiden Europa. Europa’s still with him, sort of, as the intriguing satellite orbiting Zeus’ Roman equivalent Jupiter. In fact the moons around the planet Jupiter are generally named for Jupiter’s lovers and friends. His wife is missing from the entourage, and will be until the NASA spacecraft Juno reaches Jupiter next year.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Three views of Taurus the bull and Orion the hunter for 9 p.m. on December 8, 2015. Created using Stellarium and GIMP.
11/25/11 – Ephemeris – The mythology of Taurus the bull
Friday, November 25th. The sun will rise at 7:51. It’ll be up for 9 hours and 15 minutes, setting at 5:06. The moon is new today, and won’t be visible.
Low in the east at 9 p.m. is the constellation of Orion the giant hunter. Above him is Taurus the bull. His face is a letter V shape of stars lying on its side with the bright orange-red star Aldebaran at the bottom tip of the V as its angry blood-shot eye. Orion is depicted in the sky facing with club in one hand and a shield in the other the approaching and in some depictions charging Taurus. The V of stars is a star cluster called the Hyades. The Pleiades are in his shoulder above. Taurus in Greek mythology was the guise the god Zeus when he carried off the maiden Europa. Europa’s still with him, sort of, as the intriguing satellite orbiting Zeus’ Roman equivalent Jupiter. In fact the moons around the planet Jupiter are generally named for Jupiter’s lovers and friends.
* Times, as always are for the Traverse City/Interlochen area of Michigan.
Addendum
The constellations Taurus and Orion and the Pleiades. Created using Cartes du Ciel.
Bob Moler's Ephemeris Blog 