All posts by Tom

What Would Giuseppe Think?


This is an image of Ceres taken by the Dawn spacecraft taken on 13 June 2016.

Great image! Funny think was my very first thought was what would Giuseppe think.

Giuseppe Piazzi discovered Ceres on 1801.

From his journal:
The light was a little faint, and of the colour of Jupiter, but similar to many others which generally are reckoned of the eighth magnitude. Therefore I had no doubt of its being any other than a fixed star. In the evening of the second I repeated my observations, and having found that it did not correspond either in time or in distance from the zenith with the former observation, I began to entertain some doubts of its accuracy. I conceived afterwards a great suspicion that it might be a new star. The evening of the third, my suspicion was converted into certainty, being assured it was not a fixed star. Nevertheless before I made it known, I waited till the evening of the fourth, when I had the satisfaction to see it had moved at the same rate as on the preceding days.

About Guuseppe Piazzi and the discovery of Ceres and more.




This is the final view taken by the JunoCam instrument on NASA’s Juno spacecraft before Juno’s instruments were powered down in preparation for orbit insertion. Juno obtained this color view on June 29, 2016, at a distance of 3.3 million miles (5.3 million kilometers) from Jupiter.

Juno is now in orbit around Jupiter and is apparently working perfectly!

Confirmation of a successful orbit insertion was received from Juno tracking data monitored at the navigation facility at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, as well as at the Lockheed Martin Juno operations center in Denver. The telemetry and tracking data were received by NASA’s Deep Space Network antennas in Goldstone, California, and Canberra, Australia.New Horizons


Update on Juno

The Juno spacecraft is doing great.

Juno has passed Callisto and Ganymede and will pass  Europa in an hour and a half (so that’s around 17:30 UT and then finally Io shortly after that.

The rings of Jupiter although small do possibly pose a hazard, it’s a gamble according to Dr. Scott Bolton (Juno Mission team).  It’s a unknown because we do not know how near the planet the ring extends and we will be on the inside of the known ring plane.

Another unknown will occur later at  19:30 PDT / 03:30  UTC (5 July) and that’s when Juno flies through the intense radiation although hopefully not through the very worse of it for very long.  Will the shielding protect the electronics?

No approach pictures?  No, basically all science instruments are off this time around because that burn is job number one.  The spacecraft will be rotated in such a way the solar panels are not aimed at the sun during the very first pass.

So we have: then engine burn, the radiation belts and the rings to get through.  Good luck Juno!!

Five Facts About the Juno Mission

Five facts about the Juno mission from the BBC.  The video astutely points out, the deal is not done.  The mission is depending on the insertion burn to be successful.

So important is the burn mission managers plan on turning OFF certain features of the on-board computer system just in case some sort of computer anomaly or system restart might interrupt the 35 minute “braking” burn.  The burn is scheduled to begin at 00:18 on 05 July / 20:18 PDT 04 July.

By the way that engine used for the orbital insertion is the LEROS rocket engine manufactured by Moog ISP Westcott United Kingdom.

I should have a mission update shortly after 16:15 UT.



The Juno Approach Movie

As Juno approached Jupiter a series of images were taken between the dates of 10 June to 23 June. We can see the motions of the four Galilean moons.

Notice the moon Callisto, the outermost of the four, it is much dimmer than might be expected and becomes one of the first questions for the mission scientists.

The science instruments will be turned on in a couple of days and the next close encounter between Juno and Jupiter comes at the end of August.


The Roar of Jupiter

The video represents two events for the Juno spacecraft. The first event is when the Wave instrument aboard Juno crosses the bow shock of Jupiter on 24 June. The bow shock is where the solar wind interacts with the magnetic field of Jupiter, the solar wind is slowed and heated by the planets magnetic field – think of something like a sonic-boom.

The second is the crossing of the magnetopause the boundary between the magnetic fields of the Sun and Jupiter on 25 July.   The representation is very 1950’s sci-fi, it’s great.


The Great Red Spot


In this image of Jupiter taken from the Juno cam on 28 June 2016 we can see the Great Red Spot of coming into focus.  As is the case for most images posted here you can click it for a larger version.

The image was acquired from 6.2 million km / 3.9 million miles away as the spacecraft approaches the planet towards the north pole.  The gap between Jupiter and the Juno spacecraft will quickly diminish and in just a few days the spacecraft will begin orbiting the giant planet.

The moons we can see are in order from Left to Right: Ganymede, Io, Europa.

Image: NASA/JPL-Caltech/SwRI/MSSS