Voyaging Among The Stars
Right now, space travel as we know it is plagued by a few stubborn problems, most of which boil down to striking a balance between speed and time. The faster you travel, the more energy you need. Without gravitational assists, that means more fuel will be required — and that has to be carried somehow. Faster speeds — required to reach long distances in a reasonable timeframe — also mean more difficulty slowing down.
So far, New Horizons is the fastest spacecraft ever in terms of launch velocity. Its launch speed was about 58,000 km/hr. After a flyby of Jupiter, New Horizons picked up a gravitational boost — but even still its speed was only 48,000 km/hr as it approached Pluto.
It was thanks to those gravitational flybys that Voyager 2 became the fastest spacecraft to leave our solar system. After getting boosts from the four outer planets, Voyager 2 achieved a speed of about 60,000 km/hr on its way out. To put that into context, a trip to Alpha Centauri — the closest star system to ours — would take about 78,000 years at this pace.
Furthermore, a craft making the trip would need to slow down when it arrived. Deceleration would require yet another series of gravitational flybys, which are only possible around large planets—none of which appear to orbit Proxima Centauri, the smallest star in the Alpha Centauri system. So, if there’s no possibility of a gravitational assistance, the crafts would have to bring along enough fuel to slow the craft down—which is about as much as you’d need to achieve top speed to begin with. That makes the craft heavier, and therefore harder to launch — and then you’re back to the drawing board. In short, the whole process has been long been unfeasible — until now.
Seeing The Light
Researchers are working on a way to use light to overcome these obstacles. One issue with sending a spacecraft like Voyager to another star is its mass. The Breakthrough Starshot project aims to launch extremely lightweight spacecraft — weighing only grams —into space accelerated by an array of lasers, at a mere percent of light speed. A spacecraft that slight could be slowed down using just the light of Alpha Centauri. Building such small spacecraft is outside our capabilities at the moment, but the concept is becoming more developed.
Researchers set forth the idea in the Astrophysical Journal. This approach seizes upon the fact that light exerts a minuscule amount of force on anything it hits. So, a lightweight enough craft with a large enough sail should be able to use this force to slow itself down. The idea isn’t new, but such a practically possible iteration of the concept is.
In January of 2016, NASA’s Juno spacecraft became the most distant solar-powered probe in the history of space exploration — an achievement made possible by improved solar cells and a more energy-efficient spacecraft.
Another light and sail application — the crowd-funded LightSail 2 spacecraft of the Planetary Society — completed its final end-to-end systems tests successfully. It is now set to launch in late 2017. LightSail 2’s large, reflective sails will test whether solar sailing is a feasible propulsion method for exploring further into the depths of space.
Expanding Humanity’s Reach
Developments like the Breakthrough Starshot could allow us to reach farther into space than ever before, gathering important data in our hunt for extraterrestrial life, habitable planets, and discoveries we haven’t even considered yet. Instead of a quick flyby of the Proxima system taking 95 years, a spacecraft would reach Alpha Centauri A in the same 95 years — and then slowly journey past Alpha Centauri B and Proxima Centauri, collecting data until system failures ended the trip.
These plans are still in their nascent stages, but they are based in sound science. It seems likely that small, ultralight spacecraft will be engaged in scientific missions, orbiting planets around other stars, sometime in the future.
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How Super Telescopes Work
In order to be seen, light from objects needs to reach our eyes. Therefore, objects that are far away don’t reflect enough light back for us to see them. The objective lens of a traditional telescope collects as much light as it can and focuses it on the focal point inside the telescope. The eyepiece lens then magnifies the light on the focal point, which creates an image on the retina of the person looking through it.
That being said, the lenses are an imperfect solution to the problem: different kinds of light bend at different angles and focus at different points — so, objects that are far enough away start to look blurry. Reflecting telescopes work to solve this problem by using a curved mirror to collect the reflection of the light. Because the light doesn’t pass through the mirror, it doesn’t bend like it would going through a refracting lens. In addition to functionality, reflecting telescopes are also a lot cheaper to make (even very large ones), and can “see” deeper into space.
Radio waves are a particularly special type of light invisible to the human eye, so images reflected by radio waves reveal entirely different views on our universe. Radio telescopes are also capable of reflecting images of very distant objects that are remarkably clear. The huge dish of a radio telescope works just like the reflecting telescope’s primary mirror, except that it needs to be much larger to accommodate the radio waves’ long wavelengths.
New Super Telescopes
An international consortium including Canada, China, India, Japan, and the U.S. is building the Thirty Meter Telescope (TMT) at an estimated cost of $1.5 billion. The primary mirror of the TMT is (of course) 30 meters in diameter. It features a segmented design composed of 492 hexagons, each 1.4 meters in diameter. When the TMT is complete it will be able to collect 10 times as much light as the Keck Telescope, and more than 144 times as much as the Hubble Space Telescope.
While impressive, that’s actually the least of what sets the TMT apart: it also exceeds the diffraction-limited spatial resolution (DLSR) of other telescopes currently in use. DSLR refers to a telescope’s ability to distinguish the light from objects that are close together at very long distances — rather than losing resolution to defects in the telescope itself. The TMT’s DSLR will beat out Keck by a factor of three, and will exceed Hubble’s DSLR at certain wavelengths by a factor of 10.
Visions Of The Future
The TMT will be equipped to investigate the most pressing questions in cosmology and astronomy as it explores the Milky Way and nearby galaxies, which include:
- the nature of dark matter;
- galaxy formation, as well as the nature of early galaxies;
- the births and early lives of planets and stars;
- the physics of neutron stars and other extreme objects;
- super-massive black holes; and
- time domain science: gamma ray bursts and supernovae.
Super telescopes of the past have already opened up the universe for us. The Hubble Space Telescope showed us just how massive the universe is, providing us with evidence of billions of galaxies, each one home to billions of stars like our sun. The Microwave Anisotropy Probe (MAP) spacecraft helped us discern that the universe is 13.7 billion years old.
Super telescopes of the future, like TMT, will advance our understanding of the universe in countless ways, many we can’t yet predict. Along with TMT, the super telescopes of the future such as the Wide Field Infrared Survey Telescope (WFIRST), the James Webb Space Telescope (JWST), and the Transiting Exoplanet Surveying Satellite (TESS), will be the way we find life on other planets and decide how to colonize outer space.
The post The Latest Super Telescopes Will Let You See Space Like Never Before appeared first on Futurism.
Over the last 100 years, the world has changed tremendously. For perspective, this year at Abundance 360, I gave a few fun examples of what the world looked like in 1917. This blog is a look at what the world looked like a century ago and what it looks like today. In short, in 1917, one hundred years ago, things looked a little bit different. Let’s dive in.
World Literacy Rates
- 1917: The world literacy rate was only 23%.
- Today: Depending on estimates, the world literacy rate today is 86.1%.