All posts by Tom

Will the Parker Solar Probe Melt?

Since the Parker Solar Probe will only be 3.8 million miles from the Sun temperatures in the operating area are estimated to be 1,377 degrees C (2,500 F). Yes the spacecraft could in theory melt. Unless of course you have a very robust solution and as it happens the spacecraft will be protected by an 11.4 cm / 4.5 inch carbon composite heat shield.

A demonstration:

Bluedot Festival!

If you are close enough to Cheshire UK, specifically the wonderful Jodrell Observatory you can thank your lucky stars.

The Bluedot Fesitival is in full swing and is a great way to spend some time. Oh I would LOVE to be there but that won’t be possible this year.

The festival runs 19, 20, 21, and 22 July so there is plenty of opportunity. Please go if you can, I would.

Details here: Bluedot Festival

Titan Seen in Infrared

Nice clean infrared views of the Saturn moon Titan. We never get to see these views of course, our view is normally of the none in the center.

Very nice work indeed.

NASA: These six infrared images of Saturn’s moon Titan represent some of the clearest, most seamless-looking global views of the icy moon’s surface produced so far. The views were created using 13 years of data acquired by the Visual and Infrared Mapping Spectrometer (VIMS) instrument on board NASA’s Cassini spacecraft. The images are the result of a focused effort to smoothly combine data from the multitude of different observations VIMS made under a wide variety of lighting and viewing conditions over the course of Cassini’s mission.

Previous VIMS maps of Titan (for example, PIA02145) display great variation in imaging resolution and lighting conditions, resulting in obvious seams between different areas of the surface. With the seams now gone, this new collection of images is by far the best representation of how the globe of Titan might appear to the casual observer if it weren’t for the moon’s hazy atmosphere, and it likely will not be superseded for some time to come.

Observing the surface of Titan in the visible region of the spectrum is difficult, due to the globe enshrouding haze that envelops the moon. This is primarily because small particles called aerosols in Titan’s upper atmosphere strongly scatter visible light. But Titan’s surface can be more readily imaged in a few infrared “windows” — infrared wavelengths where scattering and absorption is much weaker. This is where the VIMS instrument excelled, parting the haze to obtain clear images of Titan’s surface. (For comparison, Figure 1 shows Titan as it appears in visible light, as does PIA11603.)

Making mosaics of VIMS images of Titan has always been a challenge because the data were obtained over many different flybys with different observing geometries and atmospheric conditions. One result is that very prominent seams appear in the mosaics that are quite difficult for imaging scientists to remove. But, through laborious and detailed analyses of the data, along with time consuming hand processing of the mosaics, the seams have been mostly removed. This is an update to the work previously discussed in PIA20022.

Any full color image is comprised of three color channels: red, green and blue. Each of the three color channels combined to create these views was produced using a ratio between the brightness of Titan’s surface at two different wavelengths (1.59/1.27 microns [red], 2.03/1.27 microns [green] and 1.27/1.08 microns [blue]). This technique (called a “band-ratio” technique) reduces the prominence of seams, as well as emphasizing subtle spectral variations in the materials on Titan’s surface. For example, the moon’s equatorial dune fields appear a consistent brown color here. There are also bluish and purplish areas that may have different compositions from the other bright areas, and may be enriched in water ice.

For a map of Titan with latitudes, longitudes and labeled surface features, see PIA20713.

It is quite clear from this unique set of images that Titan has a complex surface, sporting myriad geologic features and compositional units. The VIMS instrument has paved the way for future infrared instruments that could image Titan at much higher resolution, revealing features that were not detectable by any of Cassini’s instruments.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the mission for NASA’s Science Mission Directorate, Washington. The VIMS team is based at the University of Arizona in Tucson.

The First P120C Hot Fire

Very impressive! It sounds like the test went fine here are the ESA comments:

Today’s hot firing of the P120C solid-propellant motor at Europe’s Spaceport in French Guiana proves its flight-worthiness for use on Vega-C next year and on Ariane 6 from 2020.

This marks an important milestone in the development schedule of Europe’s new-generation launchers, designed to boost our autonomy in the space arena, and maintain Europe’s global competitiveness.

The test lasted 140 seconds with the motor delivering a maximum thrust of 4650 kN, simulating the complete burn time from liftoff and through the first phase of flight.

No anomalies were seen and the performance met expectations, though full analysis will take several months.

The P120C is 13.5 m long and 3.4 m in (44.3 ft by 12.8 ft) diameter and is made using a carbon composite material and built in one segment. It will replace the current P80 as the first stage motor of Vega-C. Two or four P120Cs will be strapped onto Ariane 6 as boosters for liftoff.

This test was a collaboration between ESA, France’s CNES space agency, and Europropulsion under contract to Avio and ArianeGroup.

The next static firing will occur at the end of this year with the P120C qualification motor.

Merging Neutron Stars

Next?

NASA: Launched nearly 15 years ago on August 25, 2003, the Spitzer Space Telescope is the final mission in NASA’s Great Observatories Program – a family of four space-based observatories, each observing the universe in a different kind of light. The other missions in the program include the visible-light Hubble Space Telescope, Compton Gamma-Ray Observatory, and the Chandra X-Ray Observatory.

Over the years, Spitzer, which makes observations in the infrared spectrum, has made a plethora of discoveries, including this detection of the faint afterglow of the explosive merger of two neutron stars in the galaxy NGC 4993 on September 29, 2017. The event, labeled GW170817, was initially detected nearly simultaneously in gravitational waves and gamma rays, but subsequent observations by many dozens of telescopes have monitored its afterglow across the entire spectrum of light. Spitzer’s observation came late in the game, just over six weeks after the event was first seen, but this played an important role in helping astronomers understand how many of the heaviest elements in the periodic table are created in explosive neutron star mergers.

The telescope was named after Lyman Spitzer, Jr. (1914-1997), one of the 20th century’s great astrophysicists, who made major contributions in the areas of stellar dynamics, plasma physics, thermonuclear fusion, and space astronomy. He was laos the first person to propose the idea of placing a large telescope in space and was instrumental in the development of the Hubble Space Telescope.

Image Credit: NASA/JPL-Caltech

Juno Spots Another Volcano on Io?

Some exciting Juno results. The “new volcano” is found by looking just below the bright feature in the center of the image. Click the image for help finding the object.

Credits: NASA/JPL-Caltech/SwRI/ASI/INAF/JIRAM

NASA: Data collected by NASA’s Juno spacecraft using its Jovian InfraRed Auroral Mapper (JIRAM) instrument point to a new heat source close to the south pole of Io that could indicate a previously undiscovered volcano on the small moon of Jupiter. The infrared data were collected on Dec. 16, 2017, when Juno was about 290,000 miles (470,000 kilometers) away from the moon.

“The new Io hotspot JIRAM picked up is about 200 miles (300 kilometers) from the nearest previously mapped hotspot,” said Alessandro Mura, a Juno co-investigator from the National Institute for Astrophysics in Rome. “We are not ruling out movement or modification of a previously discovered hot spot, but it is difficult to imagine one could travel such a distance and still be considered the same feature.”

The Juno team will continue to evaluate data collected on the Dec. 16 flyby, as well as JIRAM data that will be collected during future (and even closer) flybys of Io. Past NASA missions of exploration that have visited the Jovian system (Voyagers 1 and 2, Galileo, Cassini and New Horizons), along with ground-based observations, have located over 150 active volcanoes on Io so far. Scientists estimate that about another 250 or so are waiting to be discovered.

Juno has logged nearly 146 million miles (235 million kilometers) since entering Jupiter’s orbit on July 4, 2016. Juno’s 13th science pass will be on July 16.

Juno launched on Aug. 5, 2011, from Cape Canaveral, Florida. During its mission of exploration, Juno soars low over the planet’s cloud tops — as close as about 2,100 miles (3,400 kilometers). During these flybys, Juno is probing beneath the obscuring cloud cover of Jupiter and studying its auroras to learn more about the planet’s origins, structure, atmosphere and magnetosphere.

JPL manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute in San Antonio. The Juno mission is part of the New Frontiers Program managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the Science Mission Directorate. The Italian Space Agency (ASI), contributed two instruments, a Ka-band frequency translator (KaT) and the Jovian Infrared Auroral Mapper (JIRAM). Lockheed Martin Space, Denver, built the spacecraft. JPL is a division of Caltech in Pasadena, California.