Chapter 2 Chapter 2 The Intruder

Before 2130, the radars built by humans on Mars already had the work efficiency of discovering a dozen asteroids every day.Spaceguard computers calculate their orbits and store all data.Since Ceres, the largest of these small worlds, was discovered on the first day of the 19th century, it took more than 120 years to discover the first 1,000 asteroids.Hundreds have been found and lost and found again.They exist in such a swarm that one exasperated astronomer dubbed them "the vermin of the sky."How surprised he would be to learn that the Space Guard now had the tracks of half a million asteroids.

Only five giants among them—Ceres, Pallas, Juno, Eunomia, and Wistar—are larger than 200 kilometers in diameter, and most of the rest are only the size of a rockery in a park; Almost all of them orbit outside the orbit of Mars, and only a few that run too close to the sun and may endanger the earth attract the attention of space guards.In the entire history of the solar system, the number of asteroids that may have entered the space within 1 million kilometers from the earth is less than one-thousandth of the total. This celestial body was first identified as No. 31/439 according to the year and sequence of discovery, and it was searched outside the orbit of Jupiter.This position is not unusual at all, and many asteroids even travel farther than Saturn, and then fly back toward their host star, the sun.The furthest of them all is Huuris 2, which swam so close to Uranus that it might have become a lost "moon" of that planet.However, it was unprecedented for No. 31/439 to be found by radar in such a remote place. Obviously, it must have a rare size.Based on the strength of the radar reflection, the computer reported that it was at least 40 kilometers in diameter.Such a big guy hadn't been spotted yet, and it's inconceivable that it would have gone unnoticed for so long.

Then its orbit was calculated, and the mystery was solved, only to be replaced by a greater one. 31/439 does not move periodically like a clock in an elliptical orbit like ordinary asteroids.It is a lonely wanderer among the stars, making its first and last voyage into the solar system - because it is calculated that its speed is too fast for the sun's gravitational field to catch it, and it will continue to accelerate, passing through The orbits of Jupiter, Mars, Earth, Venus, and Mercury, and then around the sun, go again into the unknown. Just then, the computer started blinking the "we found something interesting" signal.This immediately caught the attention of humans.Space Guard Headquarters was even more sensational.Astronomers decided to give it a formal name instead of a simple number.Having long exhausted the names of the gods of Greek and Roman mythology in order to name numerous celestial bodies, the names of the gods of Hinduism have now begun to be used.Therefore, 31/439 was named "Rama".

For several days the various news outlets trumpeted Rama, but coverage was difficult because of so little information.The only two facts known about this visitor are its unusual orbit and approximate size, the latter estimated from radar reflections.In the astronomical telescope, Rama is still very dim, with only the brightness of 15th-magnitude star-it is still too small to observe its shape.But as it plunges into the inner solar system, it will grow brighter and larger each month; orbiting observatories will collect more precise information about its shape and size before it disappears for good. .Given time, perhaps in a few years a spacecraft on a regular mission will circle close enough to take some clear pictures of it.An actual rendezvous seems unlikely; the energy cost of coming into contact with an object cutting the orbits of the planets at 100,000 kilometers per hour would be too great.

The ever-changing world quickly forgot about Rama, only astronomers.Their excitement grew as the months passed, as this new asteroid revealed more and more mysteries to them. First, there is the issue of Rama's brightness cycle.It simply does not.All known asteroids, without exception, have a slow brightness change that waxes and wanes every few hours.This has been confirmed for more than two centuries.This is unavoidable due to their rotation and reflecting sunlight in irregular shapes.As they wobble from side to side along their respective orbits, their sun-facing reflective surfaces constantly change, and their brightness changes accordingly.

There was no such change in Rama.Or it doesn't rotate?Or is it a perfectly symmetrical body?Both explanations seem unlikely. Things stalled for a few months, because there were no large-aperture telescopes available to observe Rama.In order to explore the far-reaching mysteries of the universe, they each have fixed tasks.Astronomy is really expensive stuff, a large piece of equipment can easily cost you a thousand dollars a minute.Dr. William Stanton could not have seized the 200-meter-diameter reflector telescope and observed Rama for a full minute had it not been for a temporary failure of a more important project he was working on.An astronomer's bad luck often turns out to be his good omen.

Stanton didn't know what he was getting until the next day, when he got the results of the data processing from the computer.Even when everything was announced on the screen at the end, it took him several minutes to grasp their meaning. The intensity of the sunlight reflected on Rama's surface turned out to be not absolutely uniform, and there was a small, though difficult to detect, variation.This change is very regular, that is to say, like other asteroids, Rama also rotates. The only difference is that each "day" of asteroids is several hours, while Rama's is only four minutes.

Stanton did some quick calculations and came up with incredible results.The rotation of this small world reaches over a thousand kilometers per hour at its equator.If you want to land on it, you can only land on its poles, and anywhere else is dangerous, because the centrifugal force at the equator is enough to throw any object with an acceleration of almost one gravity.Rama is a spinning stone that is unlikely to gather any cosmic moss.It's amazing how such an object managed to hold together without falling apart into a million pieces long ago. An object with a diameter of 40 kilometers rotates at a rate of once every four minutes - what is the analogy in astronomy?Dr. Stanton was a very imaginative man, and after a few uncomfortable minutes he jumped to the conclusion that this phenomenon was only for a collapsing star, or that Rama was a dead sun, yes A crazily rotating neutron star with a mass of 1 billion tons per cubic centimeter!

At this moment Stanton thought horribly of a classic book—H. G. Wells's.When he first read it as a child, he became interested in it and decided to become an astronomer.He couldn't shake the frightening imaginary picture in the book: an interstellar visitor collides with Jupiter and then crashes towards the sun, passing the earth, setting up violent winds and waves, and drowning the whole city in the sea!Of course, the stars described by Old Wells are fiery.But even though Rama is a cold object, its gravitational force can also produce huge damage like fire. Any interstellar object entering the solar system will distort the orbits of all the planets, and the earth will only need to move closer or farther away from the sun by 1 million kilometers, and the current climate balance will be destroyed; or the ice caps at the two poles will completely melt and flood all the lowlands ; or the seas would freeze over and the whole world locked into eternal winter—a little bias would be enough.

Thinking of this, Dr. Stanton breathed a sigh of relief—this is nonsense!He should blush at his own cranky thoughts. Rama cannot be composed of condensed matter.impossible.It is impossible for a dead solar-mass object to sneak into the solar system unnoticed.The orbits of all the planets were not unaffected; Neptune, Uranus, Pluto were thus discovered.No, it won't, it's absolutely impossible for a dead solar-mass object to slip in without being detected. However, this is also a pity.Wouldn't it be exciting to meet a dark star too?