Saturday March 3rd the outer planets Mars and Jupiter will be at a position along their respective orbits where they have the same heliocentric longitude of approximately 223o. However this does not mean that if you were to observe the two in the morning skies that they would be lined up. The are not. Rather, as this graphic shows, the two planets are lined up with each other and with the Sun, while the Earth is at a lower heliocentric longitude and not in the same line as the two planets.
Tuesday January 30th Mars and Uranus will reached their respective orbital positions that have them 180o apart. Mars will be located at approximately 207.6o and Uranus at approximately 27.6o of heliocentric longitude. This called heliocentric opposition.
Interestingly at their last heliocentric opposition, February 26th 2016, Mars was located at approximately 200.0o and Uranus at approximately 20.0o of heliocentric longitude.
Click here to go to the Qué tal in the Current Skies web site for monthly observing information, or here to return to bobs-spaces.
Wednesday evening December 27th the 10-day old waxing gibbous Moon will be a few degrees from the ringed planet Uranus. Given the dimmer 5.7 apparent magnitude of Uranus, and the considerably brighter Moon’s -12.42 apparent magnitude Uranus will not be visible. However Uranus at this apparent magnitude, and without the interference from ‘moonlight’, would be visible with the unaided-eye, and would certainly be visible with binoculars.
Nearby, below the Moon as it rises, is the dwarf Planet Eris, which at 18th apparent magnitude is definitely out of the visible range of all but larger telescopes.
Thursday October 19th the outer planet Uranus reaches a position in its orbit around the Sun when it is on the opposite side of the Earth from the Sun. This coincidentally is known as opposition, and it is an orbital position which only the planets further from the Sun than the Earth may reach.
On Thursday the outer planet Uranus will be several degrees from an even more outer planet, Dwarf Planet Eris. Both rise during the evening hours and are over the southwestern horizon before sunrise.
Ok, so how can you Moon Uranus? Yeah I know – a sad, and bad joke. Let’s put it behind us.
Sunday morning, August 13th, the 21-day old waning gibbous Moon rises within a few degrees from the planet Uranus. Both are within the eastern fish of the constellation Pisces the Fishes. Uranus ‘shines’ at just under 6th magnitude so it is possible to see the 7th main planet from the Sun with binoculars. However the reflected light from the Moon will brighten the sky more than enough to drown out the dimmer light from Uranus and most other stars in the area making them not visible.
Not that it will be visible but near the Moon on the opposite side from Uranus is one of the dwarf planets, Eris. However at nearly 19th magnitude and almost 95.729 AU, (8,898,566,474 miles ; 14,320,854,563 km) from the Earth it is all but impossible to see without some serious amateur equipment, at an observatory, or with the Hubble Telescope. Add approximately an additional 1 AU (93,000,000 miles; 1,496,68992,000 km) to get its distance from the Sun.
What did I say about enough of the ‘bad jokes’? This cartoon reminded me of the statement, “Captain, We’re orbiting Uranus searching for Klingons.”
Speaking of Uranus here is a portion of the Orbits performance video showing Uranus and some of its moons.
The Juno Spacecraft is now fully engaged in making its planned orbits around the outer planet Jupiter. Since arriving and orbital insertion the spacecraft has made 6 orbits around Jupiter sending back amazing images and advancing our knowledge of the planet and its role in the solar system.
Showing my age but I can remember how excited I was during the Voyager 1 and 2 flybys of the outer planets Jupiter, Saturn, Uranus, and Neptune during the 1980s. It was 40 years ago, Voyager 1 September 5th1977 – Voyager 2 August 20th 1977, when the spacecraft were launched. While both were targeted for a Jupiter and Saturn flyby Voyager 2 eventually had its mission rearranged so that it would fly past all four of the outer giant planets in a mission called the ‘Grand Slam’ or ‘Grand Tour’. The images from those flybys were just as exciting as the images we see from the current Juno mission albeit improved after 40 years of imaging technology advances.
So Where are the two Voyagers now? Click here to find out.
Click here to go to the NASA Video web site to see a short video (15 minutes) about the Voyager mission to the outer planets. This is part of a video series I often used in my Planetarium and classroom during the 1990s – so please realize that the graphics and animations, as well as some descriptions and some explanations are not necessarily as ‘advanced’ as things are now. However two of my heroes, Dr. Edward Stone, and Dr. Andrew Ingersoll, are featured making comments about some of the Science and discoveries.
Below is a well done video compilation of images taken by the Juno Spacecraft. Click here to go to the Vimeo web site for the original video.
Friday July 21st the position of the planet Uranus, with respect to the Earth and the Sun, places this ringed planet at what is called western quadrature. At that orbital position Uranus, and actually any outer planet, is at a 90 degree angle from the Earth as this graphic shows, and the banner graphic at the top of the page shows. Think third quarter Moon as that is a fair comparison of the relative positions of Earth, Sun, and Uranus.
At western quadrature Uranus leads the Sun across the sky from east to west as the Earth is rotating, meaning that Uranus rises before the Sun and also sets before the Sun.
This is a short video clip from a much longer video that I made as part of a live musical performance called “Orbit” at the Gottleib Planetarium in Kansas City Missouri during May 2011.