UFOs: Mirage or Martians?

The recent sightings of a 'flying saucer' in parts of Western India has revived the Unidentified Flying Object (UFO) debate. Hard-headed scientists who used to regard ufology - and ufologists - with undisguised disdain are now taking a hard new look at the phenomenon.

Minhaz Merchant

August 15, 1978 |

The recent sightings of a 'flying saucer' in parts of Western India has revived the Unidentified Flying Object (UFO) debate. Hard-headed scientists who used to regard ufology - and ufologists - with undisguised disdain are now taking a hard new look at the phenomenon.

Prof D. Lal, director of the Physical Research Laboratory (PRL), Ahmedabad, took a personal interest in the controversy, following widely reported eye-witness accounts by people in Bombay, Udaipur and Ahmednagar, of a 25-km-long, 2-km-wide flying object on April 3. The PRL has now finished examining the pictures taken by an amateur Bombay photographer and the other evidence in a full-scale study - the first of its kind undertaken in India.

Dr J.N. Desai, chief of the investigative team, has made some preliminary calculations: The object's brightness is estimated at one-tenth that of the moon and its velocity at roughly 4 km per second; it was observed for three minutes over a stretch of 1,200 km in Western India at an altitude of 60 km.

Alien Spacecraft: Prof Lal said he would not rule out the possibility of the object being an alien spacecraft. However, he stressed that it could not be a satellite or a rocket because of the time factor involved.
That such largely unsubstantiated hypothesis can gain scientific currency (and capture the public imagination) is an indication that ufologists are back in business.

Dr Jayant V. Narlikar, the world-renowned astrophysicist, who is professor of astronomy at the Tata Institute of Fundamental Research, said: "Generally speaking, I do not subscribe to a belief in UFOs. Every investigation on the subject in the West has reached a dead-end. There is as yet not a shred of evidence that flying saucers exist. When people claim to have seen such mysterious objects, they are probably just being deceived by common optical illusions."

Illusions: Temperature inversion, for instance, is one natural phenomenon that can bring about optical illusions. The effect gives rise to a sandwich of cold and warm layers of air which cause both visual and radar mirages. Virtually all UFOs recorded on radar screens have now been determined to be mirage effects arising from temperature inversion. Thousands of eye witness accounts of strange moving objects, glowing brightly in the sky can be similarly explained by known scientific effects.

In certain atmospheric conditions, with ice-crystals present in nearby cirrus clouds, a halo forms around the sun making it appear like a glowing, slowly moving flying object. Dr V.S. Venkatavardan, a fellow in the TIFR's Cosmic Ray division, said: "At night, most so-called UFOs are in reality exceptionally bright meteorites or fireballs." The rarely seen Aurora Borealis effect (commonly known as the Northern Lights) is also sometimes mistaken for a flying saucer.

Super Beings: Assuming that there is intelligent life in outer space (an assumption that is, mathematically at least, perfectly valid) which can indulge in inter-planetary travel and is, therefore, technologically far more advanced than human beings, obviously, such 'super-beings' would establish prior radio contact with earth (or, if they were so inclined, jam the world's entire radio communication system) and having disdainfully noted our backwardness, would do either of the two things: conquer us or ignore us. Since the former hasn't occurred and the latter, if it had, would make little difference, it seems likely that the only visitors from outer space, in the near future at least, will be meteorites, comets and shooting stars.

Space: Down to Earth

Anytime now, Rs 2,000 crore will go up in flames when Skylab, the largest artificial earth satellite launched so far, plunges back to earth. The objectives for which it was sent into space have been achieved during the nine months of its operation (from May 14, 1973 to February 8, 1974).

V.S. Venkatavardan

September 30, 1978 |

Anytime now, Rs 2,000 crore will go up in flames when Skylab, the largest artificial earth satellite launched so far, plunges back to earth. The objectives for which it was sent into space have been achieved during the nine months of its operation (from May 14, 1973 to February 8, 1974).

It was abandoned in space with its systems completely "turned off". Scientists had, however, hoped to revisit the space station in the next two years to recover material left in the spacecraft and discover the effect on it of long duration exposure to outer space conditions.

But the space station is in a critical condition today and may plunge down to earth anytime and at any place. It has started wobbling and is losing altitude every minute. The downward spiral is caused by the residual atmospheric drag on the satellite. Even though the atmosphere at the satellite orbit height is quite thin, it is sufficient to bring the satellite down to the lower atmosphere over a number of years where it will burn and eventually fall.

A satellite at low altitude thus has a lower lifetime in space compared to one at a higher altitude (spy satellites orbiting at very low altitudes have lifetimes of only a few days or weeks). If the satellite is small, it may be completely burnt out in the atmosphere owing to friction. If sufficiently heavy (like Skylab) a portion of it may fall on earth with a high impact speed.

Object in Space: On January 1, 1977, the number of man-made objects in near earth space was 4,141. On an average about five objects are placed into space during the launching of a single satellite. These include the discarded rockets and other hardware used in launching the satellite. Skylab revolutionized space station technology and set innumerable records in space science.

A total of 172 days were spent in the space station by three successive crews of astronauts. The missions conclusively proved that man can live for a prolonged period in space without any ill effects. Investigations were carried out in the physical sciences, bio-medical sciences and earth and space applications.

Among others, a detailed study of the sun was carried out which gave over 3,00,000 solar photographs during various phases of its activity. Further, thousands of photographs of the famous Comet Kohoutek were taken. Over 10,000 photographs of the earth and 70 km of magnetic tapes of information related to earth observations were made during the mission.

The Tata Institute of Fundamental Research, Bombay, in collaboration with scientists from the Physical Research Laboratory, Ahmedabad, exposed a stack of cosmic ray detectors for 73 days outside Skylab during the third manned mission and retrieved it for analysis of cosmic rays. These studies have given valuable information about cosmic rays - their origin and propogation in space. A new component of cosmic rays has been discovered by Indian scientists from Skylab studies.

The Fall: It was initially thought that Skylab would spiral down sometime during 1980. Its earlier anticipated fall is curiously due to the sun which controls the upper atmospheric pressure of the earth. The pressure is not a constant and varies by orders of magnitude, depending on the state of the sun. There are what are called sun spots - dark regions seen in the solar disc whose number varies periodically. From a near absence of sun spots during a "solar minimum", the number grows into a maximum and falls to a minimum again within a period of about 11 years which is called the "solar cycle".

The upper atmospheric pressure, and hence the air drag for the satellite, will be high during maximum solar activity. The sun is reaching the peak of its activity which is expected to be the maximum around 1979-80. That would be still 'safe' for Skylab if the solar activity during the present maximum is normal. But it appears that the present solar maximum will be extremely intense with the sun spot number exceeding 100 or so. If that is so, the drag on the satellite will be considerable, causing it to plunge downwards earlier than predicted.

Skylab can still be saved if a Space Shuttle is sent up and a booster rocket attached to the space station enabling it to be sent in a higher orbit. But this appears to be difficult because of a delay in the Space Shuttle project. Corrections have been carried out from the ground station at Houston, Texas, which has stabilized the spacecraft's wobble to some extent. But if the orbit is not sufficiently raised, it will quickly lose its altitude and will ultimately head towards the earth. A sudden increase in solar activity will quicken the process.

Food: The saving of Skylab is important because a number of materials were kept outside the spacecraft to discover the effects of prolonged exposure in space. Among the objects inside the space station are rehydratable thermostabilized bread pudding and beverages. A study of the retrieved material will be useful for future space programmes involving long duration flights.

Skylab left alone in space also poses a danger to the earth in that it may fall on some heavily inhabitated region. In principle its orbit could be changed so that it falls in an uninhabited area, such as the deep ocean or a desert. Thus there are two courses of action left open. Either it can be placed in an higher orbit so as to prolong its lifetime, or it can be destroyed in a pre-determined orbit with a minimum of danger to people and property on earth.

NASA's New Horizons Spacecraft Spots Pluto's Faintest Known Moons

Following the spacecraft's detection of Pluto's giant moon Charon in July 2013 and Pluto's smaller moons Hydra and Nix in July 2014 and January 2015, respectively, New Horizons is now within sight of all the known members of the Pluto system.

For the first time, NASA's New Horizons spacecraft has photographed Kerberos and Styx - the smallest and faintest of Pluto's five known moons.

It completes the Pluto family as of now. If the spacecraft observes any additional moons as it gets closer to Pluto, they will be worlds that no one has seen before.

"New Horizons is now on the threshold of discovery," said John Spencer, mission science team member from the Southwest Research Institute in Boulder, Colorado.

Following the spacecraft's detection of Pluto's giant moon Charon in July 2013 and Pluto's smaller moons Hydra and Nix in July 2014 and January 2015, respectively, New Horizons is now within sight of all the known members of the Pluto system.

Drawing ever closer to Pluto in mid-May, New Horizons will begin its first search for new moons or rings that might threaten the spacecraft on its passage through the Pluto system.

The images of faint Styx and Kerberos are allowing the search team to refine the techniques they will use to analyze those data, which will push the sensitivity limits even deeper.

Kerberos and Styx were discovered in 2011 and 2012, respectively, by New Horizons team members using the Hubble Space Telescope.

Styx, circling Pluto every 20 days, is likely just seven-21 kms in diameter and Kerberos, with a 32-day period, is just 10-30 km in diameter.

The images detecting Kerberos and Styx were taken with New Horizons' most sensitive camera, the Long Range Reconnaissance Imager (LORRI).

"Detecting these tiny moons from a distance of more than 55 million miles is amazing," added New Horizons principal investigator Alan Stern.

Other unlabeled features in the processed images include the imperfectly removed images of background stars and other residual artifacts.

Soon a Plane Could Fly Through Venus's Atmosphere

The ambitious project would see the plane cruise through the sulfurous skies of Venus for years, sampling the acidic alien atmosphere directly and observe the venusian surface from 50 km up.
 

A US aerospace company is planning to build an inflatable propeller plane that could fly through Venus's atmosphere in 2021. The ambitious project would see the plane cruise through the sulfurous skies of Venus for years, sampling the acidic alien atmosphere directly and observe the venusian surface from 50 kilometres up. However, the plane faces a battle to get USD 1 billion in funding from NASA in order to get off the ground. Called the Venus Atmospheric Maneuverable Platform (VAMP), the concept for the vehicle is currently being drawn up by the company Northrop Grumman. VAMP would have a wingspan of 55 metres with an estimated top speed of 220km/h. The ground temperature on Venus hovers around 460 degrees Celsius. Ambient surface pressure is about 90 Earth atmospheres, 'Space News' reported. "Surviving on the surface for any longer than four hours and getting high-resolution data is a challenge," said Constantine Tsang, a researcher at the Southwest Research Institute in Boulder, Colorado. VAMP, however, would fly in a more forgiving environment. It would be flown 50 to 70km above the surface of Venus, in a region of the atmosphere where the pressure is roughly equal to that on Earth. The temperature at that altitude on Venus is about 15 degrees Celsius. The plane would be carried to Venus by a spacecraft, and upon arriving in orbit around the planet, it would detach and enter the atmosphere by itself. The next New Frontiers competition is set to begin in the US government's 2016 fiscal year, which starts October 1. The winning mission would have to be ready for launch around 2021.