Nasa prepares mission to ‘touch the sun’
The US space agency has unveiled a new probe, which will set off next year to study the sun’s activity. This is the latest phase in our complex relationship with the star. How will it end?
Cost: $1.5 billion. Weight: 1,500 lbs. A 4.5 inch shield to withstand temperatures of 1,400°C. One mission: to get closer to the sun than ever before.
NASA’s Parker Solar Probe, launched next summer, will open a new era in space travel. The craft will spend almost seven years traveling to its destination, orbiting Venus seven times on the way. It will get to within 3.9m miles of the sun — a record for a man-made object.
The probe’s main purpose is to study the causes of solar wind and its relationship to the sun’s corona (see Q&A). These phenomena can have important effects on earth.
But aside from its practical aims, the mission also caters to our deep fascination with our star. To quote Nicola Fox, a senior scientist at NASA: “We will finally touch the sun.”
The sun has captivated us since time immemorial. For millennia, societies across the world associated it with life, knowledge and unerring justice.
Sun worship was practiced by everyone from the Aztecs to the Ancient Egyptians and the Romans.
Traces of these beliefs persist today. For instance, some Native American tribes still perform sun dances. But over the centuries they were mostly displaced by other ways of thinking: first by monotheistic religions that discourage nature worship, then later by science.
Scientific research has complicated our understanding of the sun. We now know that it is not an eternal celestial being but a shifting sphere of gas with an in-built expiry date. And rather than just seeing it as the giver of life, we are increasingly aware of the ways it could disrupt — and even end — human existence.
Take the corona. Instabilities within it send out highly magnetized material into space; if this reaches earth, it can wreak havoc with satellites and power grids. By one estimate, a major impact of this kind could cost the USA alone $2 trillion in damage.
Then there is the alarming prospect of the sun’s own lifespan. As it ages, it is getting hotter. In a billion years or so, scientists believe that earth’s water will start rapidly evaporating, speeding up global warming and making life hard for organisms. In roughly 5 billion years, the star will begin to expand, eventually engulfing our planet.
Here comes the sun
Science is the answer, say some. As NASA explains, the more we know about how the sun works, the better prepared we will be against its threats. Humans have a knack for working around problems. The sun will be no different.
Don’t be so sure, reply others. The sun’s dangers are the greatest we have ever faced; they will outstrip our understanding. Religion is based in large part on awe and fear. As we enter an uncertain future, sun worship could well take root again.
- Does the sun frighten you?
- Will religion ever die out?
- On your own, write down ten words that you associate with the sun. Then compare your choices as a class. Which words come up most frequently?
- Write a letter to the US president, arguing why NASA’s budget should be either increased or decreased.
Some People Say...
“If you want to shine like a sun, first burn like a sun.”
What do you think?
Q & A
- What do we know?
- Solar winds are flows of charged particles which the sun emits into the solar system. The corona is a gaseous aura surrounding the sun; its extreme heat gives the particles the velocity to escape the sun’s gravitational field. It is unstable and sometimes sends out highly magnetised material. If aimed at earth, this material can cause beautiful auroras, but can also mess with power grids, GPS systems and radio communications.
- What do we not know?
- Exactly how or why “space weather”, as all this activity is called, happens. NASA has been studying this for some time; the stated mission of the Parker Solar Probe is to “trace the flow of energy” behind the corona and solar wind. This knowledge could help us predict solar weather and protect ourselves against its nasty effects.
- Parker Solar Probe
- The probe is named after Eugene Parker, the American astrophysicist who predicted the existence of solar wind in the 1950s.
- Orbiting Venus
- This will enable the probe to shrink its orbit around the sun, bringing it closer.
- The current record holder is the Helios 2, which came to within 43.5m kilometres of the sun in 1976.
- The analogy between light and knowledge exists across cultures. Hence words such as enlightenment and illumination.
- Unerring justice
- The sun was often seen as an “unblinking, all-seing eye”, says the Encyclopaedia Britannica.
- Gods in Ancient Rome included Sol (Sun) and Sol Invictus (Unconquered Sun). The word “Sunday” comes from a translation of the Latin “dies solis” (day of the sun).
- By the National Academy of Sciences. The academy also predicted that the whole eastern seaboard of the USA could be without power for a year!
- Global warming
- As water evaporates from the earth’s surface, it is held in the atmosphere where it acts as a greenhouse gas, trapping incoming heat. This speeds up the evaporation, and so on.