Innholdsfortegnelse for EG22 i New Scientist - The Essential Guides

WE HAVE always had an itch to know what is around the next corner or over the next ridge. This same curiosity led us towards space when we began observing how orbs moved across the night sky. Then came Galileo Galilei, who used telescopes to observe mountains on the moon and spots on the sun and realised that the heavens weren’t perfect celestial spheres. In doing so, he brought the night sky down to Earth. These were just other places that must abide by the same laws of nature. In other words, he made us realise that we can go into space. Uncovering these laws let us build the tools needed to explore further – eventually sending space probes and people to the moon and beyond. This twenty-second New Scientist…

You played an important part in creating a private space industry. What initially motivated you? At the time, NASA had a very full plate and the Space Shuttle programme was expensive. Freeing up budget from human space flight was a huge motivation; we wanted to offload some of the expensive routine activities. Do you think there are good reasons to send people back to the moon now? Human space flight can offer transformative change for us. In the long term, being a single-planet species puts humanity at greater risk of extinction than if we were a multi-planet species. So it would be good to aim to go to Mars in future, and the moon is a first step. And is US human space flight in general on the right path?…

What was it like to be up there on the ISS for so long? Did you feel cooped up? I was very lucky that I got to spend almost 11 months on board the ISS as my first space flight mission. I never got cabin fever. It was pretty far into my mission before I realised, “I haven’t felt the wind on my face in a long time, I miss that.” There were definitely days where I would go over to our tiny greenhouse, which is about the size of a couple of shoe boxes, and just smell the plants. Just to smell something that was organic, that actually did a lot for me. I’ve never really thought about the smell aspect – does the space station smell like anything?…

You watched from a helicopter as the OSIRIS-REx samples landed. How tense was it? I got up at 1.30 that morning because we had some routine work to do on the spacecraft. I wear a ring that measures my heart rate and I remember it was already 120 beats per minute! This was 20 years of my career, all depending on everything going smoothly on that day. Later, I was in a helicopter, waiting for the capsule to come down. The capsule got pretty low and there should have been a drag parachute opening, but no one was calling it. I was a mess emotionally, thinking that this was going to be a disaster. But then the air force officer I was with was calling the main chute and, before…

THE RINGS After a six-and-a-half-year journey, Cassini entered orbit around Saturn on 1 July 2004 – and immediately encountered the planet’s signature feature, its rings. Pictures collected by the Voyager probes when they flew past Saturn in 1980 and 1981 suggested the planet was girdled by about 10,000 rings, each a cloud of particles tightly confined to a narrow orbit. The rings are also complex: Cassini’s images have revealed clumps, holes, gaps and other structures. Some wave-like features are due to gravitational interactions with the moons embedded in the rings, but the origin of others is unclear. The rings probably formed initially when a large moon came too close to Saturn and was ripped apart by gravitational forces. Larry Esposito, principal investigator for Cassini’s ultraviolet imaging spectrograph, says this was…

WE ARE used to living in a thick soup of atmosphere. In a cubic centimetre of air, a volume the size of a six-sided die, there are trillions of atoms. Gas, dust, water vapour, viruses, pollen and more all waft around. Just beyond our atmosphere, however, in interplanetary space, the conditions are close to a perfect vacuum. Out there, the same volume contains, on average, just five atoms. This matter mostly consists of charged particles streaming out from the sun as the solar wind. We have known for decades about this flow of material and how it creates a protective bubble around the solar system called the heliosphere. It cocoons us from high‑energy cosmic rays shooting at us from deep space – and it is a good thing too, because…

WHEN astrobiologists talk about seeking atmospheric biosignatures, they are referring to molecules known to be associated with life on Earth that we can detect from afar. We do this by looking at how the intensity of light from a host star at different wavelengths changes as a planet moves across its face, whereupon some of that light may be absorbed by the planet’s atmosphere. Different types of molecule absorb light at characteristic wavelengths, and so if we see that the intensity of starlight diminishes at certain wavelengths during a transit, this indicates the presence of a given chemical. We have never been better equipped for this search. Not only has the power of the James Webb Space Telescope to resolve spectra massively boosted our ability to probe the chemistry of…

How do we define life at the moment? A popular definition, often used by NASA, is that life is a self-sustaining chemical system capable of Darwinian evolution. Every word in there is problematic. I don’t think life necessarily needs to be chemical. It’s a much more abstract phenomenon. Life is about how information structures material objects and what objects are selected to exist, regardless of whether those things are chemical or not. As for “self-sustaining”, well, first you must define the boundary of the self. Parasites are interesting because they’re not self-sustaining, but if you include their host then they are. Life depends on its environment. A lot of the issues with defining life always come from us wanting to draw a hard boundary. We want to be able to…

What was your first view of Earth from space like? As soon as you’re out of the atmosphere, the fairings jettison and light can come through the window. Luckily for me, I was on the part of the spacecraft that was pointing towards the Earth so I could see the Pacific Ocean, with the curvature of the Earth and black space above. It was really, really bright. How would you describe the overview effect? When you look down on the Earth, you can’t see the political boundaries. Politics means absolutely nothing because you’re seeing the natural world. When you’re zipping around in low Earth orbit, in 92 minutes you’ve gone completely around the Earth. So instead of it being this huge place that you can apparently do anything to that’s…

“AS I take man’s last step from the surface, back home for some time to come – but we believe not too long into the future – I’d like to just say what I believe history will record: that America’s challenge of today has forged man’s destiny of tomorrow.” These were some of the last words spoken on the moon as NASA astronaut Eugene (Gene) Cernan climbed the ladder back into his lunar module in 1972. Contrary to Cernan’s hopes, no one has since set foot on the lonely, cratered world that orbits our own. But that is about to change, because the US is planning to send people back to the moon by 2025 and set up a permanent base there. Add to that the plans of China and…

WITH renewed push for the moon, and the lucrative returns that might result, military interest is inevitably following. “The United States is certainly aware the moon could have tremendous long-term economic potential,” says Peter Garretson, a defence expert at the American Foreign Policy Council, a US think tank. “The military doesn’t want an outpost to be threatened due to the lack of a sheriff.” Yet even in these tentative early stages, there are concerns that military activity could snowball. If we are to return to the moon, how much of a role, if any, are we comfortable with the armed forces playing? US military interest in lunar space dates back to the dawn of the space age. In 1959, the US Army proposed a crewed military outpost on the moon…

IN 1960, astronomer Frank Drake began an experiment. With a radio telescope, he studied two nearby sun-like stars, hoping to find signals that could only have been generated by life on planets orbiting these stars. He came up blank. In the six decades since Drake started the search for extraterrestrial intelligence (SETI), astronomers have kept listening, carefully and systematically. Still, we have heard nothing. One possibility is that there simply are no aliens out there – that we truly are alone. But this seems unlikely, given the vastness of the cosmos, with hundreds of billions of galaxies containing hundreds of billions of stars, most of which have at least one planet orbiting them, at least according to our burgeoning knowledge of exoplanetary systems in our own galactic neighbourhood. Jill Tarter,…

1957: THE FIRST SATELLITE It was the beginning of the space age: the launch by the Soviet Union on 4 October 1957 of Sputnik 1, the world’s first artificial satellite. With the Soviet Union and the US locked in an ideological war, the West watched with trepidation as a small, polished metal orb circled above Earth, sending a simple, bleeping signal back home. Just a month later, on 3 November, the Soviet Union chalked up another iconic first when Laika, the most famous of the Soviet space dogs, was shot into orbit on the considerably larger Sputnik 2. She didn’t make it back to Earth. For decades, the official line was that she died painlessly after about a week in orbit. New evidence unearthed in 2002, however, suggests she only…

TWENTY years to the day since Yuri Gagarin’s space flight, the US launched the world’s first reusable spacecraft into orbit. STS-1, better known as Columbia, left NASA’s Kennedy Space Center in Florida on 12 April 1981 and landed just over two days later in California. The iconic shuttles remain the only winged spacecraft to have made multiple flights into orbit, but the programme has also been marked by very public tragedy. On 28 January 1986, Challenger was set to carry the first American civilian into space. Christa McAuliffe was killed along with another six NASA crew members when the shuttle broke up 73 seconds into its flight. In 2003, damage to Columbia’s protective heat panels during launch meant it was destroyed as it re-entered Earth’s atmosphere on its return journey,…

OUR sun is no serene orb. Every now and then its fiery surface turns explosive, sending matter, energy and magnetism whirling into the surrounding vacuum. In 1859, a particularly violent solar flare-up coincided with a huge electromagnetic storm in Earth’s atmosphere. The interference caused polar auroras that could be seen as far south as the Caribbean and as far north as Auckland, New Zealand, and knocked out telegraphic systems. That was when we first grasped the power of solar storms on Earth. But what caused them remained unknown. In 1956, Eugene Parker, a young postdoctoral fellow at the University of Chicago, was investigating cosmic rays arriving at Earth from far off in the galaxy when an idea struck him. “The sun’s atmosphere, the corona, is not tightly bound. Stuff can…

1. LEAVING EARTH When Earth and Mars are at their closest, they are Struck the surface travelling about atStruck 600 55 the metres million surface per travelling kilometres apart. That sounds like Struck the surface travellingsecond at 600 metres per second a lot. at 600 But metres in terms per second of the propulsion systems needed, distance through space isn’t actually Landed safely with instruments too toLanded big measure an safely ask water, with of our heat instruments existing rocket technology. Once you are far enough from Earth, its pull drops considerably and you could cruise to Mars using a reduced thrust. The journey would take about nine months, a little longer than an astronaut’s standard six-month stint on the International Space Station (ISS). We don’t need to dream up…

WITH such a cornucopia of delight and intrigue, Jupiter was an obvious destination for our first ventures into the outer solar system. Four brief encounters with the planet came in the 1970s, courtesy of the passing probes Pioneer 10, Pioneer 11 and Voyagers 1 and 2. They gave us our first glimpses of its swirling gases, powerful magnetic field and delicate rings, as well as a closer look at its most iconic feature – the “Great Red Spot”, a vast storm that has raged since at least 1830. In 1995, NASA’s Galileo, the first craft designed to orbit Jupiter, arrived after a six-year journey from Earth. In the following eight years, it gave us our first intimate view of the planet and its moons, including the four discovered by its…

HUBBLE’S launch in 1990 was motivated by the idea that the best view of space is from space itself. Astronomers attempting to get a good view of very distant objects in the universe have problems doing that from Earth’s surface thanks to obstructions from clouds, light pollution and the distorting effects of the atmosphere. Building big telescopes on mountain tops is one solution, but Hubble offers an even better view. Named after Edwin Hubble – the US astronomer who, in the 1920s, showed through observations of distant galaxies that the universe was expanding – Hubble’s main light-collecting mirror is 2.4 metres in diameter. (By comparison, the current largest optical telescope on Earth’s surface, the Gran Telescopio Canarias on La Palma in the Canary Islands, is 10.4 metres in diameter.) It…

What is it like to work at the Jet Propulsion Laboratory? I am unusual at JPL in that I haven’t dreamed of working there since I was a child. However, I’ve had the tremendous opportunity to work on a number of incredible missions, including the European Space Agency’s Rosetta and currently the Mars 2020 Perseverance rover, and that’s what has kept me so very interested in working at JPL. I’ve been honoured to work with such amazing scientists and engineers. What kind of intelligence does the Perseverance rover, currently exploring Mars, have? Is it a smart rover? Well, smartness is a relative term. Perseverance can do much more than prior rovers, but it is still way behind what a human science and engineering team could do on Mars. For example,…