Plasma Sheet

The Sun is pretty energetic at the end of the solar cycle. This sheet of plasma above occurred on 28 July in about the same area that sunspot AR2665 is now. That sunspot, by the way, is the same one was associated with a very powerful CME on the far side of the Sun about a week ago.

There is a short video of the plasma sheet available from NASA.

NASA – A sheet of plasma blasted out into space from just behind the edge of the sun (July 28, 2017). While some material escaped into space, a portion of it was unable to break the pull of gravity and the magnetic forces nearby and can be seen falling back to the sun. The 3.5 hours of action was captured in a wavelength of extreme ultraviolet light.

Image: NASA/GSFC/Solar Dynamics Observatory

To Scale: The Solar System

A great video by Wylie Overstreet and Alex Gorosh.

I even do this every now and then myself just for fun and I get a bit of exercise in the process. I don’t do it quite the way Wylie and Alex did  as I just pace off this distances but even so, it is very interesting.

This is a GREAT activity for children!  Depending on what scale you use for distance you all you will need is a flat piece of ground, like say a football pitch. Even at one step per 10 million kilometers you can get a pretty long ways away from the starting point so plenty of room is helpful.

You can change the scale to fit your needs as long as you are looking at distance and not necessarily planetary sizes; also a good exercise for youngsters to exercise their brains during the school holiday.

To get you started have a look at this page from the Lunar and Planetary Institute.


This ‘family portrait’ shows a composite of images of Jupiter, including it’s Great Red Spot, and its four largest moons. From top to bottom, the moons are Io, Europa, Ganymede and Callisto. Europa is almost the same size as Earth’s moon, while Ganymede, the largest moon in the Solar System, is larger than planet Mercury.
While Io is a volcanically active world, Europa, Ganymede and Callisto are icy, and may have oceans of liquid water under their crusts. Europa in particular may even harbour a habitable environment.
Jupiter and its large icy moons will provide a key focus for ESA’s JUICE mission. The spacecraft will tour the Jovian system for about three-and-a-half years, including flybys of the moons. It will also enter orbit around Ganymede, the first time any moon beyond our own has been orbited by a spacecraft.
The images of Jupiter, Io, Europa and Ganymede were taken by NASA’s Galileo probe in 1996, while the Callisto image is from the 1979 flyby of Voyager.

The JUICE mission sounds like a typical ESA mission — ambitious and well planned.  It should be exciting, even if there is a long tome until launch.  Read more about the JUICE mission here.

Curiosity Climbing Mt Sharp

As seen from orbit (look at the center of the image). Click for a larger view.

NASA – the feature that appears bright blue at the center of this scene is NASA’s Curiosity Mars rover on the northwestern flank of Mount Sharp, viewed by NASA’s Mars Reconnaissance Orbiter.  Curiosity is approximately 10 feet long and 9 feet wide (3.0 meters by 2.8 meters).

The view is a cutout from observation ESP_050897_1750 taken by the High Resolution Imaging Science Experiment (HiRISE) camera on the orbiter on June 5, 2017.  HiRISE has been imaging Curiosity about every three months, to monitor the surrounding features for changes such as dune migration or erosion.

When the image was taken, Curiosity was partway between its investigation of active sand dunes lower on Mount Sharp, and “Vera Rubin Ridge,” a destination uphill where the rover team intends to examine outcrops where hematite has been identified from Mars orbit.  The rover’s surroundings include tan rocks and patches of dark sand. The rover’s location that day is shown at as the point labeled 1717. Images taken by Curiosity’s Mast Camera (Mastcam) at that location are at

As in previous HiRISE color images of Curiosity since the rover was at its landing site, the rover appears bluer than it really is. HiRISE color observations are recorded in a red band, a blue-green band and an infrared band, and displayed in red, green and blue.  This helps make differences in Mars surface materials apparent, but does not show natural color as seen by the human eye.

Lower Mount Sharp was chosen as a destination for the Curiosity mission because the layers of the mountain offer exposures of rocks that record environmental conditions from different times in the early history of the Red Planet. Curiosity has found evidence for ancient wet environments that offered conditions favorable for microbial life, if Mars has ever hosted life.

The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., Boulder, Colorado. NASA’s Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project and Mars Science Laboratory Project for NASA’s Science Mission Directorate, Washington.

Image Credit: NASA/JPL-Caltech/Univ. of Arizona

Doomed Comets

Comets coming close to (but not actually impacting) the Earth are very cool. Comets getting too close to the sun are doomed and we get to see them thanks to our space based observatories.


COBALT (CoOperative Blending of Autonomous Landing Technologies) strives to provide the higest quality precision navigation solution ever tested for NASA space landing applications.

The technologies included a navigation doppler lidar (NDL), which provides ultra-precise velocity and line-of-sight range measurements, and the Lander Vision System (LVS), which provides terrain-relative navigation.

NASA’S Armstrong Flight Research Center – Through flight campaigns conducted in March and April aboard Masten Space Systems’ Xodiac, a rocket-powered vertical takeoff, vertical landing (VTVL) platform, the COBALT system was flight tested to collect sensor performance data for NDL and LVS and to check the integration and communication between COBALT and the rocket. The flight tests provided excellent performance data for both sensors, as well as valuable information on the integrated performance with the rocket that will be used for subsequent COBALT modifications prior to follow-on flight tests.

Expedition 52 Launch – Replay

Replays later today, in the mean time NASA TV and that’s pretty good, so if you don’t usually get to watch, here you go.

NASA – NASA astronaut Randy Bresnik, Sergey Ryazanskiy of Roscosmos and Paolo Nespoli of ESA (European Space Agency) will launch at 11:41 a.m. (9:41 p.m. Baikonur time) from the Baikonur Cosmodrome in Kazakhstan. The Expedition 52/53 crew will spend more than four months together aboard the orbital complex before returning to Earth in December. Video of prelaunch activities from the crew’s activities in Baikonur will air July 24-27 on NASA TV.

After launching, the trio will travel for six hours in the Soyuz MS-05 spacecraft before docking to the space station’s Rassvet module at 6 p.m. NASA TV coverage of the docking will begin at 5:15 p.m.

Great Red Spot


The image above is Jupiter’s Great Red Spot in true color.

NASA – This image of Jupiter’s iconic Great Red Spot (GRS) was created by citizen scientist Björn Jónsson using data from the JunoCam imager on NASA’s Juno spacecraft.

This true-color image offers a natural color rendition of what the Great Red Spot and surrounding areas would look like to human eyes from Juno’s position. The tumultuous atmospheric zones in and around the Great Red Spot are clearly visible.

The image was taken on July 10, 2017 at 07:10 p.m. PDT (10:10 p.m. EDT), as the Juno spacecraft performed its seventh close flyby of Jupiter. At the time the image was taken, the spacecraft was about 8,648 miles (13,917 kilometers) from the tops of the clouds of the planet at a latitude of -32.6 degrees.

JunoCam’s raw images are available at for the public to peruse and process into image products.

NASA/JPL-Caltech/SwRI/MSSS/Bjorn Jonsson

Saturn’s Haze

What a great image from Cassini! Click the image for a larger version and you can see the haze in the very upper reaches of Saturn’s atmosphere.

NASA – This false-color view from NASA’s Cassini spacecraft gazes toward the rings beyond Saturn’s sunlit horizon. Along the limb (the planet’s edge) at left can be seen a thin, detached haze. This haze vanishes toward the left side of the scene.

Cassini will pass through Saturn’s upper atmosphere during the final five orbits of the mission, before making a fateful plunge into Saturn on Sept. 15, 2017. The region through which the spacecraft will fly on those last orbits is well above the haze seen here, which is in Saturn’s stratosphere. In fact, even when Cassini plunges toward Saturn to meet its fate, contact with the spacecraft is expected to be lost before it reaches the depth of this haze.

This view is a false-color composite made using images taken in red, green and ultraviolet spectral filters. The images were obtained using the Cassini spacecraft narrow-angle camera on July 16, 2017, at a distance of about 777,000 miles (1.25 million kilometers) from Saturn. Image scale is about 4 miles (7 kilometers) per pixel on Saturn.

Image: NASA/JPL-Caltech/Space Science Institute