Paul M. Sutter is an astrophysicist who Ohio State University, the host ask the astronaut and “space radio,” and the author “your place in the universeSutter contributed this article to Space.com Expert Voices: Op-Ed & Insights.
The space is huge – huge, and if you want to successfully explore the depths of our planet, galaxy Galaxy You will need a reliable system. The new proposal attempts to make this method as simple as possible: use binary stars to create a reference frame for the Milky Way.
inside our solar system Interplanetary spacecraft rely on worldsystem used for navigation When we send a radio signal to the spacecraft and then respond. We can then use the response delay to calculate the distance. We can also monitor spacecraft in the sky. and by combining all that information We can determine the location of the spacecraft in the solar system and provide that information to the spacecraft.
Gallery: vision of interstellar spaceship travel
We can also use Doppler shift of those radio waves to estimate the speed at which the spacecraft moves away from Earth. with the use of plates scattered around the world We can measure the delay from the signal of the spacecraft reaching one dish relative to another. When we combine that information with location information. We have a six-dimensional locking system on the spacecraft: three-dimensional position and three-dimensional velocity.
This method relies on a network of ground radar systems. All of this is in constant communication with the spacecraft. This technique works for spacecraft within the solar system. And they̵7;re almost NASA’s twins. probe.
But every interstellar mission will require a new approach: they will have to navigate on their own. in principle These spacecraft can use onboard systems such as clocks and gyroscopes. But interstellar missions will take at least several decades. And minor errors and instability in the systems on those planes will undoubtedly lead those spacecraft astray.
There is also an option to use pulsar, periodically rotate an object that appears to tremble or tremble This is because each pulsar has a unique spin duration. These objects can therefore serve as reliable beacons for deep space missions. But this only works within relatively small bubbles near our solar system. Because the rotational measurements may be contaminated with space dust. And when you forget which pulsar is a pulsar? show you lost
second star on the right
Therefore, interstellar spacecraft need a simple and reliable way to estimate their positions within galaxies, new paper. Just posted to the arXiv.org print-ahead server. proposed such a solution: the stars themselves.
This technique uses a very old concept: parallax. If you point your finger to your nose and close your eyes alternately your finger will tremble The obvious change in position comes from a new perspective as you go from eye to eye. If you do the same while looking at a distant object. The object will appear to wiggle much less.
through parallax that scientists can measure distances before reaching starand through parallax where spacecraft traveling far from home can get directions. Before launch, we load the spacecraft with an accurate map of all known stars in the vicinity of our galaxy. Then when the spacecraft flew out of the solar system fast. It measures the relative distances between several pairs of stars. as it moves The stars near the spacecraft appear to have changed dramatically. while the distant stars are relatively stable.
By measuring multiple pairs of stars and comparing them with the original Earth-based catalog, the spacecraft can determine which star is which. and how far away from those stars This gives the spacecraft an accurate 3D position in the galaxy.
Finding the speed of a spaceship is a little more difficult. and based on the strange theory of special relativity. because of the limitation of speed of lightIf you move fast enough Objects may appear in a different position than they really are. Especially The object’s position will appear to shift in the direction you’re moving. This effect is called a discrepancy. and can be measured from the world as our planet orbits the sun The stars also seemed to sway gently in the sky.
As long as the spacecraft moves fast enough (And if we want interstellar missions in the past decade, not millennials, we have to.) On-board systems will be able to measure this discrepancy. By observing which stars are moving away from their expected positions and how much. A spacecraft can calculate its 3D speed.
when using parallax measurements The spacecraft will be able to restore the complete six-dimensional coordinates within the galaxy. It knows where it is and where it is going.
How accurate is this technique? According to the report, If the spacecraft were able to measure the positions of only 20 stars to within 1 arc-second of accuracy, (Arc second is equal to 1/60 of arc minute, which itself is 1/60th of a degree) can also be specified. The position within the galaxy has an accuracy of 3. astronomical unit (AU) and its velocity does not exceed 2 kilometers per second (1.2 miles per second). One AU equals the average distance between the Earth and the sun — about 93 million miles (150 million km) — so 3 AU equals 279 million miles ( 450 million km) sounds like a lot. But it’s a peanut compared to thousands of interstellar AUs.
We have precise locations for more than 20 stars, so we can load spacecraft with a catalog of hundreds of millions of stars to use on their journey. Each spacecraft can be measured to help pinpoint its location more accurately.
Now all we need is an interstellar spaceship.
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