Stargazing in September: the Parker probe goes to the sun

It was a cliffhanger. On Saturday, August 11, NASA's powerful Delta 4 heavy-lift launcher, second behind Elon Musk's massive Falcon Heavy, had to launch an iconic space probe into the Sun. Countdown proceeded. All systems looked good. And then – panting! At 1 minute and 55 seconds before take-off, the launch was interrupted. There was a problem with the rocket's helium systems.

The next day, the team tried again. Seeing the Delta 4 s flying in the dark skies of a morning Cape Canaveral was a great relief. We watched the massive rocket launchers fall into the Atlantic and blew several sighs of relief. Parker Solar Probe – the payload of the rocket – was heading towards the sun.

Nobody could have been more relieved than Eugene Parker, a 91-year-old American solar physicist. He is the only one alive to have had a spaceship named after him. And – surprisingly – it was the first space launch he had ever been to.

Parker was ahead of his time in the 1950s, when he suggested that the sun should have time. And, in particular, the solar wind: a stream of protons and electrons under tension that boils our local star at speeds of up to a million kilometers per hour.

Everyone did not believe it. But he was right How good! The solar wind can be a ferocious beast, especially when the sun is turning into maximum magnetic activity (which occurs about every 11 years). Then, the sunspots enamel the surface of the sun. These are places where the magnetic field stirred by our Sun breaks down and causes all kinds of electromagnetic chaos when their field lines are intercepted, creating a short circuit powered by a star. Explosive solar flares throw powerful charged particles into the solar system. In the Sun's outer atmosphere – the corona – vast clouds of gas called coronal mass ejections burst into space, posing an even more dangerous threat.

The impact on the earth? The first is beautiful and benign: we can see the aurora. These rays and these luminous curtains, visible at the high north and south latitudes, are caused by the attraction of magnetism: the charged particles of the Sun go towards our magnetic poles.

But that's not good news. The unpredictable weather conditions of the Sun are crucial for satellites in Earth orbit. He can knock out their electronic devices. And when you think about how much we depend on weather and communications satellites, it is vital that we have warnings. And with manned flights – and space tourism – destined to expand, it is essential to protect future astronauts from radiation risks.

Even on the ground, we are not safe. Extreme solar activity can disrupt power lines and communication links. On one occasion, he eliminated the Quebec Stock Exchange. Now, there is a catastrophe,

At the time of writing, the Parker probe is en route to Venus, where it will use the gravity of the planet to reduce its orbit. The first meeting with the Sun will take place on November 1st (carrying a memory card of one million benefactors who support the mission).

Over the next seven years, Parker will make repeated dives in the solar corona. At its closest, it will be only 3.4 million kilometers from the surface of the Sun (for comparison, the Earth is 93 million kilometers away). And it will be heated to 1400 ° C. To protect its sensitive instruments, the rugged probe has a 4.5-inch thick carbon heat shield that took 10 years to develop. When it goes around the Sun, it will be the fastest man made object, traveling at 430,000 mph.

What would we learn from the Parker Probe? First, why is the crown so hot? Compared to the surface of the sun (5,500 ° C), it is millions of degrees. And what are the causes of eruptions and coronal mass ejections? How can we be warned and protect ourselves?

In the end, the Parker probe is a bold and visionary project. What a way to get closer to our local star.

What's up?

We are losing our evening star this month: brilliant Venus has blazed in the west after sundown in the last six months, but by the end of September it will sink in twilight. On his left, the giant Jupiter also sinks in the southwest horizon and goes to bed around 21h.

To the south, however, two bright planets still hold the fort. The bright reddish "star" is Mars, it gradually fades as the fast-moving Earth moves away from the red planet. On its right, the creamy yellow Saturn is low among weak stars of Sagittarius. The world of the ring is right next to the first quarter moon on September 17th.

The farthest planet, Neptune, is closest to the Earth on September 7, located in the constellation Aquarius. But the term "closest" still means 4.3 billion kilometers, and you'll need binoculars or a small telescope to detect it.

At the beginning of the month too, if you are an early bird, you will be able to see the closest planet to the Sun, the tiny Mercury, low in the east around 5am.

We also have a comet right now, though, again – with frustration – it is too dark to be seen with the naked eye. But sweep the sky below the brilliant Capella star with good binoculars to try to spot the fuzzy patch that's comet Giacobini-Zinner. This celestial visitor travels the solar system every 6.6 years and is closest to the Earth on September 10th. Wait until December for a comet not to be missed.

Personal diary

September 6th, morning: Mercury very close to Regulus
September 7th: Neptune to the opposition
September 9thAt 7:01 pm: New moon
September 10: Comet Giacobini-Zinner closest to the Earth
September 12: Crescent moon near Venus
September 13: Crescent moon near Jupiter
September 15th: Crescent moon near Antares
September 17th, 0.15am: Moon in the first quarter, near Saturn
September 19th: Moon near Mars
September 23, 2.54h: Autumn Equinox
September 25, 3:53: full moon; Mercury at the westernmost elongation
September 29: The moon occults the Hyades

Heather Couper and Nigel Henbest's latest book: "Philip's 2018 Stargazing"