10/10/2019 – Ephemeris – Saturn’s moon Enceladus may have the building blocks of life

Ephemeris for Thursday, October 10th. Today the Sun will be up for 11 hours and 15 minutes, setting at 7:07, and it will rise tomorrow at 7:52. The Moon, 3 days before full, will set at 5:23 tomorrow morning.

Even though the Cassini mission to Saturn ended two years ago its data will be will be studied for decades by scientists around the world. One of Cassini’s discoveries were geysers of water ice being ejected from the small moon Enceladus, that creates Saturn’s tenuous E ring. Two instruments aboard Cassini, a mass spectrometer and a cosmic dust analyzer, discovered organic compounds in the geysers and the E ring. Further analysis by German geologists found nitrogen-oxygen molecules among the ice grains. These are like the constituent compounds that make up amino acids which on Earth make up the proteins of life. Currently both NASA and the Europeans are considering return missions to Enceladus.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Enceladus, a small moon of Saturn spews continues to geysers of water rom cracks in its south polar region indicating an ocean below its frozen icy exterior. Sampling the plumes with the right instruments may detect life on this small world without the need for drilling. Credit: NASA/JPL – Caltech

How organic compounds are attached to ice grains and ejected from Enceladus. Credit: NASA/JPL – Caltech.

10/06/2017 – Ephemeris – GTAS meeting tonight – Remembering Cassini

Ephemeris for Friday, October 6th. The Sun will rise at 7:46. It’ll be up for 11 hours and 26 minutes, setting at 7:13. The Moon, 1 day past full, will rise at 8:10 this evening.

Tonight’s meeting, at 8 p.m. at Northwestern Michigan College’s Rogers Observatory, of the Grand Traverse Astronomical Society (GTAS) will feature yours truly and a program I’m calling Remembering Cassini. On a planet nearly a billion miles from earth the intrepid spacecraft called Cassini met its planned fate burning up in its atmosphere. It was a mission that lasted nearly 20 years, and orbited the ringed planet for 13 of those years, viewing the planet, its rings and moons from all angles, tasting the atmosphere of Titan, the geysers of Enceladus, and finally, at the end, the atmosphere of its host planet Saturn. We’ll have images, videos, and sounds of those alien worlds. At 9 p.m. there will be a star party featuring the Moon and Saturn

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

 

09/14/2017 – Ephemeris – Cassini will go out in a blaze of glory tomorrow morning

Ephemeris for Thursday, September 14th. The Sun will rise at 7:20. It’ll be up for 12 hours and 33 minutes, setting at 7:54. The Moon, 1 day past last quarter, will rise at 2:05 tomorrow morning.

Just about 24 hours from now the Cassini spacecraft will end its 20 year mission to Saturn and its 13 years of orbiting the planet. Monday, 4 days ago, it passed the great moon Titan for the last time, giving it one last gravitational boost into a suicidal plunge into Saturn’s atmosphere. At 7:55 tomorrow morning EDT (11:55 UTC), Cassini is expected to lose its stabilization in the thin upper atmosphere or Saturn and lose its connection with the Earth. It is expected to burn up, traveling at 70,000 miles an hour to become a part of the planet it investigated for 13 years. Instead of recording data for transmission to Earth later, it will be taking real-time atmospheric sampling, transmitting immediately up to the very end.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

An artist’s visualization of Cassini slipping between the rings and the atmosphere of Saturn. Credit NASA/JPL.

Here’s a link to yesterday’s news conference at JPL on the end of the Cassini Mission:  https://youtu.be/gs-dscW95PE.

Link to Emily Lakdawalla’s Planetary Society post on the final days of Cassini including NASA TV coverage:  http://www.planetary.org/blogs/emily-lakdawalla/2017/0911-cassini-eom-timeline.html.

09/04/2017 – Ephemeris – Cassini has only 11 days to go.

Ephemeris for Labor Day, Monday, September 4th. The Sun will rise at 7:08. It’ll be up for 13 hours and 4 minutes, setting at 8:13. The Moon, 2 days before full, will set at 6:16 tomorrow morning.

In 11 days, the school bus sized Cassini spacecraft, which has orbited Saturn for the last 13 years will make it’s final plunge into Saturn’s atmosphere to burn up. Cassini’s controllers at the Jet Propulsion Laboratory decided after finding the small moon Enceladus had an internal ocean that it was venting into space with interesting compounds, that it could possibly harbor life, so leaving Cassini derelict orbiting Saturn among the moons, was thought not to be a good idea, in case the unsterilized spacecraft were to crash into Enceladus. So since this spring Cassini was directed to make a series of orbits that took it inside the rings, and on the final orbit to plunge into Saturn’s atmosphere to burn up.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

An artist’s visualization of Cassini Flying between the planet and the rings. Credit NASA/JPL.  Click on the image to enlarge.

04/25/2017 – Ephemeris – The Cassini spacecraft is on its last 22 orbits of Saturn

Ephemeris for Tuesday, April 25th.  The Sun rises at 6:41.  It’ll be up for 13 hours and 58 minutes, setting at 8:40.  The Moon, 1 day before new, will rise at 7:08 tomorrow morning.

In the early hours of last Saturday, Earth Day, The Cassini spacecraft, orbiting Saturn for the last nearly 13 years, made its last pass of Saturn’s giant moon Titan.  Over the past 13 years Cassini has been using Titan as a kind of fulcrum to leverage its orbits of Saturn, returning time and time again to both study this strange moon and to propel it via gravity assists into a myriad of orbits.  This time however, with one last gravitational assist, Cassini was flung into a series of 22 daring orbits which will take it into a couple of thousand mile gap between the rings and the planet.  On orbit 22, if it doesn’t collide with an errant ring particle, Cassini will burn up in Saturn’s atmosphere, going something like 70,000 miles an hour on September 15th.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

In its planned last 22 orbits of Saturn, the Cassini spacecraft will pass between the innermost ring and the planet itself. Credit NASA, JPL.

02/21/2017 – Ephemeris – Finding Saturn this morning and Cassini’s future

Ephemeris for Tuesday, February 21st.  The Sun will rise at 7:32.  It’ll be up for 10 hours and 47 minutes, setting at 6:19.  The Moon, 3 days past last quarter, will rise at 4:48 tomorrow morning.

This morning the crescent Moon will act as a pointer to the planet Saturn.  The ringed planet will appear to the right of our Moon.  Saturn’s rings will show in any telescope with 20 times magnification or greater.  Out at Saturn for the last 13 years and for the next 7 months the robot spacecraft Cassini has been orbiting the ringed planet using gravity assists from the giant moon Titan as a fulcrum to leverage itself into many different orbits to study Saturn’s rings and collection of moons.  In a bit over seven months it’s fantastic journey will be over.  Low on fuel, it will plunge between the rings and the cloud tops, spiraling in towards its doom September 30th into the planet’s atmosphere so as not to contaminate the icy moons which could possibly harbor life.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Using the Moon to locate Saturn in the southeast at 7 a.m. or earlier on February 21, 2017. The Moon is enlarged to show it better. Created using Stellarium.

The Cassini spacecraft at Saturn. Credit: NASA/JPL.

The shepherd satellite Prometheus leaving a wake in Saturn’s outer F Ring. Credit: NASA/JPL.

06/10/2014 – Ephemeris – Our Moon and Saturn’s largest moon Titan

Ephemeris for Tuesday, June 10th.  Today the sun will be up for 15 hours and 29 minutes, setting at 9:26.   The moon, 3 days before full, will set at 4:51 tomorrow morning.  Tomorrow the sun will rise at 5:57.

Tonight the planet Saturn will be near the bright gibbous Moon.  One might need a bit of help locating it in the Moon’s glare.  Saturn is to the right and slightly above the Moon.  Saturn has a few moons of its own.  The count’s up to 62, with another apparently forming from one of Saturn’s rings as monitored by the Cassini spacecraft now in orbit of Saturn.  Cassini, which has about three years left in its mission, entered orbit of Saturn 10 years ago next month after a 7 year journey to get there.  One of the most intensively studied moons is Titan, whose haze foiled the earlier Voyager spacecraft, Cassini and it’s Huygens lander have shown us earthly terrain and methane seas.  Titan is easily seen in small telescopes near Saturn.

Addendum

Saturn and the Moon tonight at 11 p.m., June 10, 2014. Created using Stellarium.

Just Saturn and the Moon showing the moon’s gibbous phase at 11 p.m. June 10, 2014. Created using Stellarium.

Saturn and its moons including Titan at 11 p.m. June 10, 2014. Created using Stellarium.

Titan, as Voyager would have seen it, but photographed by Cassini. Credit: NASA/JPL/Space Science Institute.

Titan as seen in the infrared by the Cassini spacecraft. Credit: NASA/JPL/Space Science Institute.

Seas and lakes at Titan’s north pole seen by radar from the Cassini spacecraft. Credit: NASA/JPL-Caltech/GSFC.

Image mosaic of Titan from the descending Huygens Lander. Credit: ESA/NASA/Univ. of Arizona.