NASA launches spacecraft on bold mission to 'touch' the Sun
Sunday, August 12, 2018, 11:52 AM - NASA's Parker Solar Probe launched into space early Sunday morning, on an ambitious new mission to attempt what has never been attempted before - to 'touch' the Sun.
The Sun may be the largest object in our solar system, but we have never visited it, opting to instead observe it only from a safe distance. Until now, that is.
The Parker Solar Probe lifted off from Cape Canaveral, at 3:31 a.m. EDT on Sunday, August 12, to fly closer to the Sun than any previous spacecraft has ever come, in an effort to unlock the mysteries of the solar corona, and the solar wind that streams out from the corona into space.
"This mission truly marks humanity’s first visit to a star that will have implications not just here on Earth, but how we better understand our universe," said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate, according to a Sunday press release. "We’ve accomplished something that decades ago, lived solely in the realm of science fiction."
DARING THE HEAT
Over the next seven years, this spacecraft will make seven close passes by Venus, which will slingshot it through a total of 26 scheduled fly-throughs of the Sun's intensely hot atmosphere - the corona - getting closer and closer, until it reaches a distance of around 6.25 million kilometres from the Sun's 'surface'.
That's around 10 times closer than Mercury's average distance to the Sun, and it will be over seven times closer than the 43.2 million km record for a human-built object, set by the Helios 2 spacecraft in 1976.
We won't have wait long for its first record-breaking flyby, though.
According to NASA, in October of this year, the Parker Solar Probe will pick its first gravity assist from Venus, and make its first plunge through the outer reaches of the corona in November, coming to within 24 million kilometres of the Sun.
By sampling the environment of the corona, the probe will help answer some key questions about our home star - perhaps most importantly, why is the Sun's corona, which can reach temperatures into the millions of degrees, so hot compared to the Sun's surface, which has a temperature of roughly 5,500°C. We have some clues to this mystery from other missions (such as the concept of 'microflares'), however the answers are far from settled.
"This is a piece of heliophysics science we all really wanted for a long time, since the 1950s," Stuart Bale, a UC Berkeley professor of physics who is one of four principal investigators for the mission, told NASA. "For me personally, I’ve been working on the probe since it was approved in 2010, but I really spent a large part of my career getting ready for it."
Protected behind a new carbon-composite heat shield, the probe's instruments will remain at roughly room temperature as they gather information in a region of the corona that reaches temperatures of around 1,400°C.
The details of the Parker Solar Probe's protective heat shield. Credit: Greg Stanley/Johns Hopkins University
A NEW 'SPACE WEATHER' STATION
Similar to how 'weather' refers to the motion of winds and storms, and how the properties of those phenomena (precipitation, lightning, tornadoes, etc) can affect us, 'space weather' refers the motion and behaviour of the solar wind, as well solar flares and 'solar storms' - the immense clouds of particles, also known as coronal mass ejections (CMEs), which can erupt into space - and the associated impacts that these phenomena have on Earth and our technologies.
Space weather, from the Sun to its impacts here on Earth. Credit: NASA
Here on Earth, weather forecasting has become quite advanced, and is improving all the time. Part of the reason for this is that we have thousands of weather stations that are used to sense the weather as it happens, all around the world, to provide us with an abundance of data to feed into our forecast models.
When it comes to space weather, however, we have far fewer weather stations collecting data, primarily because it typically costs billions of dollars to put one into space. Most weather satellites (GOES, Meteosat and Himawari, the ones that primarily keep tabs on Earth weather) have solar wind instruments. There's also ACE, WIND and DSCOVR, out at Lagrange Point 1, beyond the Moon's orbit, between the Sun and Earth. Missions such as the Solar Dynamics Observatory (SDO), the Solar and Heliospheric Observatory (SOHO) and the twin Solar Terrestrial Relations Observatory (STEREO) spacecraft keep a constant watch for sunspots, solar flares, coronal holes and CMEs.
The fleet of heliophysics spacecraft and satellites, which observe and study the Sun and solar wind. Credit: NASA
Even with the coverage we do get, the timing of the readings we get is a problem, as it can take days for the activity spotted near the Sun to reach the satellites set up in orbit around Earth. With that much time passing in between, it's the equivalent of detecting a hurricane forming in the tropical Atlantic Ocean, and then not seeing it again until it's only a few hours from making landfall in Halifax.
Having more information, and more timely information, from much closer to the Sun, and especially from within the solar corona, can go a long way to improving our forecasts of space weather.
This is of critical importance, in this day and age, given our dependence on technology, because an exceptionally powerful solar storm could have disastrous impacts on our technologies in space, and on our power grids here on Earth's surface.
In September of 1859, Earth saw the impacts of the strongest solar flare and coronal mass ejection ever noted. This 'Carrington Event' caused the Northern Lights to extend far into the southern United States, and it disrupted telegraph communications for weeks.
If a similar event occurred today, the impacts would most certainly cause satellite failures, but it would also result in a global blackout that could take months to recover from, and cost the global economy close to $1 trillion.
It may seem unlikely that we'll ever see this happen, however we only narrowly avoided such an event, back in the summer of 2012.
WATCH THE LAUNCH
Did you miss the early Sunday morning launch of NASA's Parker Solar Probe? Watch it in replay, via the embedded video below.
Early morning rocket launches are often the most spectacular to view, so this is one you might not want to miss!
Author's note: A previous version of this article stated that the Parker Solar Probe will make only seven (7) passes through the corona. The seven passes are actually in reference to its flybys of Venus, which will propel it closer and closer to the Sun, for the total of 26 scheduled passes through the corona. The last of these will be on December 7, 2025. Apologies for any confusion this has caused.