Skepticism greets claim of
possible alien microbes
Jan. 4, 2006
Special to World Science
A paper to appear in a scientific journal
claims a strange red rain might have dumped
microbes from space onto Earth four years ago.
But the report is being greeted with a shower
of skepticism from scientists who say extraordinary claims require
extraordinary proof—and this one hasn’t got it.
The scientists agree on two things, though. The
rain contained particles that look like cells, at least superficially. And no
one knows what they are.
particles have much similarity with biological cells though they are devoid of
DNA,” wrote Godfrey Louis and A. Santhosh Kumar of Mahatma Gandhi University
in Kottayam, India, in the controversial paper. “Are these cell-like particles
a kind of alternate life from space?”
The study is the latest chapter in a a mystery that began when
the colored showers fell in parts of India 2001. Researchers said
the specks might be dust or a fungus, but it remained
The new study includes an analysis of the chemistry of the particles, a survey of where they fell and an assessment of
the various explanations. It concludes that the specks, which vaguely resemble
red blood cells, might have come from a meteor.
A peer-reviewed research journal,
Astrophysics and Space Science, has agreed to publish the paper. The journal sometimes publishes unconventional
research, but normally stops well short of
venturing into any generally acknowledged fringe science, such as claims of
If the particles represent alien life forms, said Louis and Kumar, it would fit with a longstanding theory
called panspermia, which holds that life forms could travel around the
universe inside comets and meteors.
These objects would thus “act as vehicles for spreading life in the universe,”
they added. They posted the paper online
this week on a database where astronomers often post research papers.
They said a meteor seems to have broken up in the atmosphere hours before the red rain.
John Dyson, managing editor of
Astrophysics and Space Science, confirmed by email that the journal has
accepted the paper for publication. But he said he hasn’t read the paper, as
his co-managing editor, the European
Space Agency’s Willem Wamsteker, handled it. Wamsteker died several weeks ago at
“I’ve had a very very brief glance at the manuscript. It looks shall I say
‘interesting’??” wrote Dyson, of the University of Leeds, U.K., in an
Other researchers expressed disbelief. “I really, really don’t think
they are from a meteor!” wrote microbiologist Jack Szostak of Harvard
University in Cambridge, Mass., of the particles, in an email.
Previous claims of microbes from meteors have
failed to ultimately convince many scientists. Nor is this the first report of
red rain of biological origin, Szostak wrote, though it seems to be the most
detailed to date.
Szostak added that the chemical tests the
Indian scientists employed aren’t very sensitive. The so-called cells are
admittedly “weird,” he added, saying he would pass the paper along to
microbiologist friends to see what they think the particles may be.
“I don’t have an obvious explanation,” wrote noted origins-of-life
researcher David Deamer of the University of California Santa Cruz, in an
They “ look like real cells, but with a very thick cell wall. But the leap to an extraterrestrial form of life
delivered to Earth must surely be the least likely hypothesis. There is so much more to be done before making such a
claim,” he added, citing several additional chemical tests that could be
Many scientists consider the panspermia
theory itself plausible. But while “panspermia may well be possible, I’m just not so sure that this is a case of
it,” wrote Lynn J. Rothschild of the NASA Ames Research Center in Moffett
Field, Calif., in an email.
The story of the specks began on July 25, 2001, when residents of the southwestern Indian state of Kerala began
seeing scarlet rain in some areas.
“Almost the entire state, except for two northern districts, have reported these unusual rains over the past week,” the
BBC online reported on July 30. “Experts said the most likely reason was the presence of dust in the atmosphere which colours the water.”
The explanation didn’t satisfy everyone.
The scarlet rain “is eluding explanations as the days go by,” the newspaper
Indian Express reported online on Aug. 6. The publication said an Indian research center, the Centre for Earth Science Studies, had discarded an initial hypothesis that a streaking meteor triggered the rain, in favor of the view that the particles were spores from a fungus.
But “the exact species is yet to be identified. [And] how such a large quantity of spores could appear over a small region is as yet unknown,” the paper quoted center director M. Baba as saying.
Baba didn’t immediately return an email from World Science this week.
The red rain continued to appear sporadically for about two months, though most of it fell in the first 10 days, Louis and Kumar wrote.
“The striking red colouration of the rainwater was found to be due to the suspension [mixture] of microscopic red particles having the appearance of biological cells,” they wrote. “These particles have no similarity with usual desert dust.”
At least 50,000 kg (55 tons) of the particles have fallen in all, they wrote. “An analysis of this strange phenomenon further shows that the conventional atmospheric transport processes like dust storms etc. cannot explain this phenomenon.”
“The red particles were uniformly dispersed in the rainwater,” they wrote. “When the red rainwater was collected and kept for several hours in a vessel, the suspended particles have a tendency to settle to the bottom.”
“The red rain occurred in many places during a continuing normal rain. Vessels kept in open areas clearly away from trees and house roofs also collected red
rainwater,” the paper continued.
“It was reported from a few places that people on the streets found their cloths stained by red raindrops. In a few places the concentration of particles were so great that the rainwater appeared almost like
The precipitation, the researchers added, had a “highly localized appearance. It usually
occur[ed] over an area of less than a square kilometer to a few square kilometers. Many times it had a sharp boundary, which means while it was raining strongly red at a place a few meters away there were no red rain. The time duration of a typical red rain was not long; usually it lasted for a few minutes to less than about 20 minutes.”
The scientists compiled charts of where and when the showers occurred based on local newspaper reports.
The particles look like one-celled organisms and are about 4 to 10 thousandths of a millimeter wide, the researchers wrote, somewhat larger than typical bacteria.
“Under low magnification the particles look like smooth, red coloured glass beads. Under high
magnifications (1000x) their differences in size and shape can be seen,” they wrote.
vary from spherical to ellipsoid and slightly elongated… These cell-like particles have a thick and coloured cell envelope, which can be well identified under the microscope.” Very few had broken cell envelopes, they added.
The particles lacked any observable nucleus, the core DNA-containing compartment that animal and plant cells have, the researchers wrote. Chemical tests indicated they also lacked DNA,
the gene-carrying molecule that most types of cells contain. They also seem to
contain no proteins, a key component of known life forms, Louis wrote in an
Nonetheless, Louis and Kumar wrote that the particles show “fine-structured
membranes” under magnification, like normal cells.
Within the outer envelope there seems to be an
“inner capsule,” they added, which in some places “appears to be detached from the outer wall to form an empty region inside the cell. Further, there appears to be a faintly
visible mucus layer present on the outer side of the cell.”
“One characteristic feature is the inward depression of the spherical surface to form cup like structures giving a squeezed appearance,” which varies among particles, they added.
“The major constituents of the red particles are carbon and oxygen,” they wrote. Carbon is the key component of life on Earth. “Silicon is most prominent among the minor constituents” of the particles, Louis and Kumar
added; other elements found were iron, sodium, aluminum and chlorine.
“The red rain started in the State during a period of normal rain, which indicate that the red particles are not something, which accumulated in the atmosphere during a dry period and washed down on a first rain,” the pair wrote.
“Vessels kept in open space also collected red rain. Thus it is not something that is washed out from rooftops or tree leaves. Considering the huge quantity of red particles fallen over a wide geographic area, it is impossible to imagine that these are some pollen or fungal spores which have originated from trees,” they added.
“The nature of the red particles rules out the possibility that these are dust particles from a distant desert source. These red particles do not have any similarity with the usual desert dust,” they wrote. Also, “Particles of this type are not found in Kerala or nearby place. The origin of these particles is unknown.”
One easy assumption is that the particles “got airlifted from a distant source on Earth by some wind system,” they added, but this leaves several puzzles.
“One characteristic of each red rain case is its highly localized appearance. If particles originate from distant desert source then why [was] there were no mixing and thinning out of the particle collection during transport”?
“It is possible to explain this by assuming the meteoric origin of the red particles. The red rain phenomenon first started in Kerala after a meteor airburst event, which occurred on 25th July 2001 near Changanacherry in Kottayam district. This meteor airburst is evidenced by the sonic boom experienced by several people during early morning of that day.
“The first case of red rain occurred in this area few hours after the airburst event. This points to a possible link between the meteor and red rain. If particle clouds are created in the atmosphere by the fragmentation and disintegration of a special kind of fragile cometary meteor that presumably contain[s] a dense collection of red particles, then clouds of such particles can mix with the rain clouds to cause red rain,” they wrote.
“The atmospheric fragmentation of the fragile cometary meteor can be the reason for the geographical distribution of the red rain cases in an elliptical area of size 450 km by 150 km. Maximum cases of red rain occurred in Kottayam and nearby districts.”
“From this, it can be inferred that while falling to the ground at low angle, the meteor has been travelling from north to south in a south-east direction above Kerala with a final airburst above Kottayam district. During its travel in the atmosphere it must have released several small fragments, which caused the deposition of cell clusters in the atmosphere from north to south above Kerala.”
The researchers didn’t comment on whether the particles show any purposeful behavior reminiscent of
life—or, if they indeed are life forms, whether they were still alive when
they reached Earth.
Alive or dead, they seem to have some staying power: “Even after storage in the original rainwater at room temperature without any preservative for about
four years, no decay or discolouration of the particles could be found.”
* * *
Send us a comment
on this story, or send
it to a friend