Ear of the Earth in ruins
One of the most important and largest instruments in the history of astronomy in the world, the Arecibo radio telescope in Puerto Rico, collapsed days after its demolition was announced. This means not only the end of a certain phase of space exploration, but also the disappearance of a pop culture icon known not only for scientific achievements, but even for popular films.
On December 2020, 6.55 at exactly 900 hours 150 minutes local time, the XNUMX-ton platform suspended at a height of XNUMX meters above the observatory canopy collapsed. First, one of the pillars of the structure (southwest) was damaged, as a result of which the 900-ton platform hit the canopy of the 305-meter telescope (1). The fall also damaged the two remaining towers and the surrounding observatory buildings. During the disaster, another check of the technical condition of the suspension structure was carried out, thanks to which it was possible to capture this moment on video.
Distinguished Explorer and Movie Star
Radio telescope it has been running continuously since 1963 November 38. The radio telescope dish was designed and built by specialists from the American Cornell University in a karst funnel from 778 1 2 x XNUMX meter aluminum panels supported by steel reinforcement. Its shape is spherical (not parabolic like most radio telescopes). This is due to the way the radio telescope is pointed at the signal: the dish was stationary, and the receiver moved. Alone the receiver was placed on a 900-ton structure (Platform), suspended at a height of 150 meters on 21 ropes attached to three reinforced concrete columns. It contained the second and third dishes, which focused the reflected waves on the antenna. Receiver mobility made it possible to direct the radio telescope to any point of the 40-degree cone around the zenith. Close proximity to the equator allowed Arecibo .
His original work was study of the upper part of the earth's atmosphere, ionosphere. However, it soon began to be used as universal radio observatory for various types of research and observations. astronomy observes objects in the universe, studying them at radio frequencies.
Question in range radio waves shows a number of cosmic phenomena, for example, pulsars - magnetized, spinning stars. The observatory provided the first solid evidence for the existence of such an object, later known as a neutron star. They were also used to identify the first example of a binary pulsar (two magnetized neutron stars orbiting a common center of mass), a discovery that later won the Nobel Prize in Physics.
Telescope it also contributed to the reversal of the stars in 1992. It has also been used for decades to listen to signals and track near-Earth asteroids. In recent years, the radio telescope has supported research leading to new discoveries of gravitational waves. In addition, thanks to him, to detect organic molecules in a galaxy far, far away and register the first repeating cyclic radio bursts (FRB).
The radio telescope also became a movie star. It was the site of the climactic duel in Goldeneye (2), the next installment of the James Bond adventure with Pierce Brosnan in 1995. Two years later, in 1997, he starred in the acclaimed sci-fi drama Contact, alongside Hollywood stars such as Jodie Foster and Matthew McConaughey. He was also seen in the series "From the X Archive" and in the horror film "Genre".
2. Shot from the film "Golden Eye" in the scenery of the radio telescope in Arecibo
The day the ropes finally let go
During these 57 years of operation, it has been modernized several times. In 1974 a new canopy skin was added with better signal reflection parameters. In 1997, a Gregorian parabolic antenna with two reflectors was installed. By the way, to strengthen the carrier system, another carrier rope was added, two for each tower. At the same time, due to the modifications made, the weight of the devices in the suspension structure of the platform increased by more than 250 tons.
In 2017, Hurricane Maria broke one of the ropes and damaged the skin panels. Three years later, in August last year, one of the cables supporting the metal platform above the telescope dish broke. The cable, breaking away, destroyed a significant part of the lantern. The University of Central Florida, which primarily operates the facility, offered a solution to stabilize the structure. However, in early November, another cable broke.
Engineers have been studying the design since the first accident in August. Based on the analysis of the stresses acting on the second cable, they concluded that the remaining cables were probably weaker than previously thought, and there was a risk of collapse of the entire supporting structure. It was found that the huge installations could not be repaired without creating a potentially lethal hazard for the workers involved in such an operation. Puerto Rican officials then announced radio telescope disassembly fearing for safety.
A few weeks after these decisions were made, the structure of the upper platform collapsed, recorded on video recordings from two places - a room in the control center of the observatory and from трутеньwho flew over the observatory, watching the cables and towers.
Engineers assessed the damage and concluded that all three of the telescope's support towers had broken, causing the 900-ton platform to fall into the canopy below. They also fell on the bowl carrier cables of the radio telescope. The observatory's science center was also heavily damaged by fallen cables.
American National Science Foundation (NSF), which manages the object, after the November reports on the technical condition of the object, despite the need for its demolition, planned to save as much of the observatory as possible so that in the future the object could serve as a scientific and educational center, and in the future it would be possible to restore the observatory in the previous mode. It remains to be seen how the December crash will affect these plans and whether the foundation will be able to move all of the archival data collected by the telescope to off-site servers.
China has a bigger bowl
Scientists are concerned about projects that were carried out with the participation of Arecibo radio telescopeand also revoke it observatory significantly reduces the level of provision of planet Earth with human civilization. It is about monitoring the so-called objects near the earth (NEO) in which the device participated.
In November, NASA released a statement in which, among other things, we read: “The capability of the Arecibo planetary radar funded by NASA’s Near-Earth Observation (NEO) Program (…) has enabled NASA to fully characterize the exact orbits, sizes, and shapes of many NEOs within radar range, after their discovery as part of large-scale research projects using optical telescopes. However, there is no tragedy, because NASA has it in stock. Goldstone Observatory in California, which serves the same purpose, but, as you know, a pair of eyes (in this case, perhaps ears) is more than one.
On the other side of the world, he began working in early 2020. radio telescope larger than Arecibo. Chinese XNUMXm spherical aperture telescope (FAST), in Guizhou Province. It is currently the most sensitive telescope on Earth. In January 2020, the Chinese government announced the start of official operations using the device.
FAST is currently the most sensitive low frequency radio telescope in the world. FAST, such as radio telescope in Arecibo, has a stationary main antenna, but thanks to wave sensors moving above the antenna mirror, both radio telescopes can view objects that are not at the zenith, while FAST can study objects farther from the zenith than the Arecibo radio telescope.
3. Chinese radio telescope FAST
FAST operates in the range of 0,7-3 GHz. The purpose of radio telescope research is to detect pulsars, both in our Galaxy and beyond, to study molecules in interstellar space, to search for variable stars, and to search for extraterrestrial life (within the framework of the SETI program). It is expected to be able to detect signal transmissions from alien civilizations over 1000 light-years away.
However, will China's giant telescope be as accessible to American and foreign scientists as Arecibo? Would it be possible to use it for testing other than those planned by China? This is yet to be seen. It remains to be seen whether a successor to the preeminent Puerto Rican observatory will appear in Arecibo or elsewhere.
