Tag Archives: solar science

Parker extends length of science operations during upcoming fifth solar fly-by

The science team for the Parker Solar Probe have decided to extend the period the spacecraft’s instruments are operating during its fifth close fly-by of the Sun, based on the data they have obtained from the first four fly-bys.

On May 9, 2020, NASA’s Parker Solar Probe began its longest observation campaign to date. The spacecraft, which has already completed four progressively closer orbits around the Sun, activated its instruments at a distance of 62.5 million miles from the Sun’s surface, some 39 million miles farther from the Sun than a typical solar encounter. The four instrument suites will continue to collect data through June 28, markedly longer than the mission’s standard 11-day encounters.

The nearly two-month campaign is spurred by Parker Solar Probe’s earlier observations, which revealed significant rotation of the solar wind and solar wind phenomena occurring much farther from the Sun than previously thought. The earlier activation of the science instruments allows the team to cover a larger range in order to trace the evolution of the solar wind as it moves away from the Sun.

Perihelion will occur on June 7 at a distance of 11.6 million miles from the Sun. That will match the previous record set during Parker’s previous orbit for the closest solar fly-by ever. They will then follow this with another fly-by of Venus, which will tighten the orbit even more.

Parker to extend instrument operations in future solar fly-bys

The engineering and science team for the Parker Solar Probe have decided they can turn on its science instruments for a longer period during future solar fly-bys, and have now done so for its upcoming third approach.

Parker Solar Probe turned on its four instrument suites on Aug. 16, 2019 — earlier than during its previous two solar encounters, extending the observation period from 11 days to about 35 days.

During the spacecraft’s first two solar encounters, the science instruments were turned on when Parker was about 0.25 AU from the Sun and powered off again at the same distance on the outbound side of the orbit. (One AU, or astronomical unit, is about 93 million miles, the average distance between the Sun and Earth.) For this third solar encounter, the mission team turned on the instruments when the spacecraft was around 0.45 AU from the Sun on the inbound side of its orbit and will turn them off when the spacecraft is about 0.5 AU from the Sun on the outbound side.

This decision will allow them to get more data about the solar wind from farther from the Sun.

Ten planetary probes track a solar eruption through the solar system

The path of an October 2014 solar eruption was tracked by ten different spacecraft, including Curiosity on the surface of Mars, as its blast moved outward through the solar system.

The measurements give an indication of the speed and direction of travel of the CME [Coronal Mass Ejection], which spread out over an angle of at least 116 degrees to reach Venus Express and STEREO-A on the eastern flank, and the spacecraft at Mars and Comet 67P Churyumov–Gerasimenko on the western flank.

From an initial maximum of about 1000 kilometers per second (621 miles per second) estimated at the sun, a strong drop to 647 kilometers per second (402 miles per second) was measured by Mars Express three days later, falling further to 550 kilometers per second (342 miles per second) at Rosetta after five days. This was followed by a more gradual decrease to 450–500 kilometers per second (280-311 miles per second) at the distance of Saturn a month since the event.

The CME was first detected by solar observatories Proba-2, SOHO, Solar Dynamics Observatory, and STEREO-A.It was then tracked as it moved outward by Venus Express, Mars Express, MAVEN, Mars Odyssey, Curiosity, Rosetta, Cassini, and even New Horizons and Voyager 2.

On my last appearance on Coast to Coast, I was specifically asked if the probes to Venus, Mars, and other planets have the capability to track solar events. I knew that the Voyager spacecraft had equipment to do this, but was unsure about other planetary probes. This article answers that question.

SDO not returning data

For reasons that remain unexplained, the Solar Dynamics Observatory (SDO) did not return to science mode after it passed through the Moon’s shadow on August 2nd.

The only information about this on the SDO webpage simply states, ” The spacecraft did not go back into Science mode at the end of the transit. SDO FOT members are looking into the issue.” Spaceweather.com notes that “Since the transit no new data have appeared on SDO public websites.”

SDO has only been in orbit for six years. It would be a shame to lose it so quickly.

UPDATE: It appears that engineers are getting SDO back into operation. Hat tip James Fincannon.

Big solar storm not so big

The uncertainty of science: A new analysis of the the 1859 giant solar storm, the first ever detected and dubbed the Carrington event after the scientist who discovered it, suggests that its strength was not global as previously believed, and that it only effected a few spots on Earth.

Up until now the Carrington event has been considered the strongest solar storm to ever hit the Earth, and has been used by the solar satellite industry as a wedge to demand funding for solar warning satellites, claiming that if a similar storm was to ever hit the Earth again without warning, it would destroy civilization as we know it. This new data suggests that this threat has been over-stated.

Why am I not surprised?

ISEE-3 engine burn

The major course correction burn for ISEE-3 was only partially successful today.

We managed to conduct the first segment (composed of 63 thruster pulses) but encountered problems with the second and halted the remainder of segment firings. Today’s burn was supposed to be 7.32987 m/s. We’re looking at data and formulating a plan for tomorrow. Our window tomorrow (Wednesday) at Arecibo opens at 12:39 pm EDT and extends to 3:26 pm EDT.