Life on Mars?

Mars is the fourth planet from Sun, and the last of the inner planets. Mars is about half the size of Earth and has two moons, Phobos and Deimos. Its surface is red due to the oxidation of iron in the soil. The Martian atmosphere is 100 times less dense than that of Earth and primarily made up of Carbon Dioxide. Although Mars does have seasons, the temperature only varies from cold to extremely cold.

The earth-based observations of Mars paved the way for spacecraft exploration of the planet. So many questions had been raised about Mars and there were so few answers. Did life exist on Mars in the past or present? Was water present on the planet? If so, what form was it in? What was the atmosphere composed of and what were its dynamics? Could Mars be used to tell us more about the evolution of both Earth and our solar system?

The combination of the thin atmosphere and low temperatures make it impossible for water to exist as a liquid on the surface of Mars. It would either freeze or evaporate. The Carbon Dioxide, which freezes to form Northern and Southern Polar caps, also exists only in solid and gaseous states, leaving the possibility that there is no liquid on Mars (at least at the surface). There are, however, many features on the surface of Mars which appear to have been created by great volumes of liquid. The current lack of water and erosion by liquids on Mars has kept the surface nearly unchanged for billions of years. This offers geologists a look into the ancient past of the planet as they view craters, volcanoes and canyons. If there was liquid water to form the distinct features on Mars that means that there was a medium in which life could develop. Only recently have we found the first evidence for life on Mars, in the ALH meteorite. The study of the origin of life on our planet and others, called exobiology, is of great interest to many scientists.

Mars is smaller and, because of its greater distance from the Sun, cooler. It has seasons similar to Earth's because the tilt of its rotational axis (axial inclination) to the plane of its orbit about the Sun is about the same as Earth's. Interestingly, unlike Earth the significant eccentricity (elliptical shape) of the martian orbit means that the seasons on Mars are also affected by varying distance from the Sun. In the case of Earth, because of its almost circular orbit, our seasons result simply from the tilt of the Earth's rotation axis.

The mean distance of Mars to the Sun is about 228 million kilometers. As noted above, the martian orbit is quite eccentric which leads to a difference of nearly 42 million kilometers between the furthest distance from the Sun (called "aphelion") and the closest distance ("perihelion"). As for any body in a gravitationally bound orbit, Mars travels more swiftly in its orbit when it is close to the Sun than when it is distant. As a result the duration of the four martian seasons varies one from another, unlike the case on Earth where each season lasts for just one quarter of the year.

According to Newton's gravitational law, the velocity of Mars is maximum at perihelion and minimum at aphelion, thus the duration of seasons shows an important variability. In the Martian northern hemisphere, winter is short and relatively "mild" while summer is long and cool. Conversely for the southern hemisphere summer is short and relatively hot while winter is long and cold. Currently, the North Pole is inclined away from the sun at perihelion but the situation goes through a cycle every 75.000 years.

The energy received by the Martian surface over the year is in direct proportion to the orbital eccentricity. The eccentricity is not fixed but, is under the gravitational influence of the other planets (especially Jupiter). The eccentricity cycles and at times the orbit is more circular. As the planet changes from an elliptic orbit to a quasi-circular one, the energy balance strongly differs from one epoch to another. There would be "warm periods" where increased sublimation of polar CO2 ice would lead to the release of more gas into the atmosphere, thus to a greater atmospheric pressure. As the inclination of the planetary spin axis is also subject to significant cyclic variation, it is suspected that the distribution of surface heating by the Sun should have experienced cyclic change over the millenia. This cycling of the martian orbit and of its spin axis make Mars an unusually variable planet. Thus Mars may well once have been quite different from the way we see the planet today.

10 Strangest Frogs

Malagasy Rainbow Frog

The Malagasy rainbow frog lives in the rocky dry forests of Madagascar's Isalo Massif, where it breeds in shallow temporary pools found in canyons. This species is well adapted to climbing

in its rocky surroundings, and can even scale vertical surfaces! When threatened, this frog will inflate itself as a defence mechanism against predators.

Transparent Frog

Hyalinobatrachium pellucidum, also called as glass or crystal frog
because you can see through its transparent flesh (right down
to its guts).This guy's not new, but he's definitely endangered,
so the finding is heartening for environmentalists.

Atelopus Frog

The atelopus frog is known by many names such as the clown frog
or the Costa Rican Variable Harlequin Toad. Whatever you call
the frog, it is a neo-tropical toad that was once quite wide
spread living throughout Costa Rica and Panama. The species
is listed as critically endangered and is thought to be living
primarily in Panama today.

World's Smallest Frog

Generally speaking, higher altitude means larger animals. But the
world's smallest known frog species lives high in the Andes
Mountains of southern Peru, between 9,925 and 10,466 feet.

World's Largest Frog

The goliath frog or Conraua goliath is the largest extant anuran
on Earth.It can grow up to 13 inches (33 cm) in length from
snout to vent, and weighs up to 8 lb (3 kg). This animal has
a relatively small habitat range,mainly in West Africa
(near Gabon). The goliath frog can live up to
15 years. Goliath frogs eat scorpions, insects and smaller frogs.
These frogs have acute hearing but no vocal sac.

Red Mantella Frog

As suggested by the name, the Red Mantella has an orange/red
dorsal surface. These frogs are small, reaching a size of
2.5 centimetres(1 in) in length. It is is a small, terrestrial
frog native to Madagascar.

Poison Dart Frog

Poison dart frog, like this sapphire-blue species, is the common name
of a group of frogs in the family Dendrobatidae which are native to
Central and South America. Unlike most frogs, species are active
during the day, and often exhibit brightly-colored bodies.
Although all dendrobatids are at least somewhat toxic in the wild,
levels of toxicity vary considerably from one species to the next, and
from one population to another. Many species are critically
endangered.These amphibians are often called "dart frogs"
due to indigenous Amerindians' use of their toxic secretions
to poison the tips of blowdarts.

Ornate Horned Frog

The ornate horned frog can grow up to six inches long and inhabits
Uruguay, Brazil, and northern Argentina. While it may look like
a lifeless pincushion, it's quick to lunge when lizards, small rodents,
birds, or other frogs blunder by.

Chile Darwin's frog

The Chile Darwin's frog was fairly regularly seen until around 1978,
since when it seems to have disappeared, and the species may now
be extinct. This species, which lives in the leaf litter on the forest
floor, has an unusual method of parental care; the male takes
the fertilised eggs from the nest into his vocal sac where they
hatch into tadpoles after approximately eight days. When he
starts to feelthe newly hatched tadpoles wriggling, the male
carries them to a stream where he expels the young. Here
they complete metamorphosis.

Vietnamese Mossy Frog

Theloderma corticale, or the Vietnamese mossy frog, is a species
of frog in the Rhacophoridae family. It is found in Vietnam
and possibly China. Its natural habitats are subtropical or
tropical moist lowland forests, intermittent freshwater marches,
and rocky areas. The common name of the mossy frog arises
from the fact that its skin is a mottled green and black that
resembles moss growing on rock, and forms an effective
form of camouflage.

Some people have this frog as a pet. The price of this beautiful
animal isabout $45-$75 (each).

10 of the World's Strangest Plant Species

Welwitschia mirabilis:World's Most Resistant Plant
It's not pretty to look at, but Namibia's plant Welwitschia Mirabilis can truly claim to be one of a kind. There really is nothing like it. Welwitschia plant consists of only two leaves and a sturdy stem with roots. That's all! Two leaves continue to grow until they resemble the shaggy mane of some sci-fi alien. The stem thickens, rather than gains in height, and can grow to be almost 2 meters high and 8 meters wide. Their estimated lifespan is 400 to 1500 years. It can survive up to five years with no rain. The plant is said to be very tasty either raw or baked in hot ashes, and this is how it got its other name, Onyanga, which means onion of the
desert.

Dionaea muscipula: the Venus Fly Trap

The Venus Fly Trap is the most famous of all carnivorous plants 

due to the active and efficient nature of its unique traps. It may be

famous, but it's also threatened. The plant's two hinged leaves are

covered in ultra sensitive fine hairs that detect the presence of

everything from ants to arachnids. Trigger the hairs and snap! 

The trap will shut in less than a second.

Rafflesia arnoldii: World's Largest Flower

There is one exotic and rare plant you wouldn't likely want to 

grow anywhere near your landscape no matter how famous it

would make you for doing so. That would be growing the largest

flower in the world. This exotic, very rare, speckled, though

not particularly pretty, rust colored flower is called Rafflesia

Arnoldii.

Rafflesia Arnoldii, recently assigned to the Euphorbiaceae family,
is the biggest individually produced flower in the world. It gets to
be 3 feet across and weighing a whopping 15- 24 pounds. That's
pretty darn big but still you would not like this flower in your
perennial bed. Why is that? If you could mimic a rainforest
type environment for this plant, it gives off a most offensive
odor when in bloom. This scent is somewhat like rotting meat.
This is why it is often called the Corpse Plant by some natives
of Indonesia where it originates.

Its blossoms only last three days to a week. But in those few
days it needs a miracle or two just for survival. This hideous
smell it produces attracts pollinating insects to it to help perpetuate
the species. But even when this happens only 10-20 percent
of the tiny seedlings make it. With any luck in nine months it blooms.

Desmodium gyrans: the Dancing Plant

Darwin called the plant Hedysarum; modern botanists call it 

either Desmodium Gyrans, or more correctly these days, 

Codariocalyx Motorius. Its common name is Dancing Grass

or Telegraph Plant or Semaphore Plant -- after the leaf 

movements, which resemble semaphore signals. For all of its

uses this plant is easy to grow, dancing happily on a sunny 

windowsill and watered when dry. Some say it dances best

to the "Greatful Dead!"

Euphorbia obesa: the Baseball Plant

Euphorbia Obesa, also known as the Baseball Plant, is endemic

to the Great Karoo region of South Africa. Unsustainable 

harvesting by plant collectors who value Euphorbia obesa for

its interesting and curious appearance has severely impacted

wild populations. Consequently, national and international 

legislation have been enacted to protect remaining populations.

While Euphorbia obesa remains endangered in its native habitat,

it has become very common in cultivation. By growing large 

numbers of Euphorbia obesa, nurseries and botanical gardens

have been working to ensure that specimens being traded and

sold among plant collectors are not obtained from the wild.

Amorphophallus titanum: the Corpse Flower

A flower taller than a man, stinking strongly of putrefying roadkill

and colored deep burgundy to mimic rotting flesh, sounds like

something from a low-budget science fiction movie. But Indonesia's

titan arum—or "corpse flower," as known by locals—is a real,

if rare, phenomenon, pollinated in the wild by carrion-seeking

insects. This Indonesian plant, called titan arum or amorphophallus

titanium, has the world's biggest inflorescence. Due to its fragrance,

which is reminiscent of the smell of a decomposing mammal, the

Titan Arum is also known as a carrion flower, the "Corpse flower",

or "Corpse plant".

Baobab: the Bottle Tree

Baobab is the common name of a genus (Adansonia) containing

eight species of trees, native to Madagascar, mainland Africa

and Australia. Also known as the Bottle Tree, not only do they

look like bottles, but the trees typically store around 300 liters

of water! No wonder why they often live over 500 years!

Dracaena cinnabari: the Dragon Blood Tree

Dracaena Cinnabari is a Dragon Tree native to the Socotra 

archipelago. It is also referred to as the Dragon Blood Tree 

and Socotra Dragon Tree. It is one of the most striking of 

Socotra's plants, a strange-looking, umbrella-shaped tree.

It was first formally described by Isaac Bayley Balfour in 

1882. A miniature Icon of this tree is in Windows as

Network-Icon. Its red sap was the dragon's blood of the ancients,

sought after as a medicine and a dye.

Mimosa púdica: the Shy Plant

Mimosa Pudica (pudica = shy), or the Sensitive Plant, has a 

curiosity value: the compound leaves fold inward and droop 

when touched or shaken, re-opening within minutes. The species

is native to South America and Central America, but is now a 

pantropical weed. Who would know that plants have feelings too?

Selaginella lepidophylla: the Resurrection Plant

Also known as Rose of Jericho, the Selaginella Lepidophylla is

a species of desert plant noted for its ability to survive almost 

complete desiccation; during dry weather in its native habitat, 

its stems curl into a tight ball and uncurl when exposed to

moisture. It is native to the Chihuahuan Desert.

10 Things Global Warming Could Change Forever

Great Barrier Reef may be gone in 20 years

The Great Barrier Reef will be so degraded by warming
waters that it will be unrecognizable within 20 years. Charlie
Veron, former chief scientist of the Australian Institute of
Marine Science, told The Times: “There is no way out, no
loopholes. The Great Barrier Reef will be over within
20 years or so.” Once carbon dioxide had hit the
levels predicted for between 2030 and 2060, all
coral reefs were doomed to extinction, he said. “They
would be the world's first global ecosystem to collapse.
I have the backing of every coral reef scientist, every
research organization. I've spoken to them all. This is
critical. This is reality.”

Amazon Rain Forest may turn into a desert

Teeming with millions of species and one-fifth of the world's

fresh water, the Amazon is the world's largest tropical rainforest.

However, global warming and deforestation are reversing the

forest's role as a carbon sink, converting 30-60% of the 

rainforest into dry savannah. Projections show the forest 

could disappear completely by 2050.

Sahara Desert may become green

Scientists are seeing signals that the Sahara desert and

surrounding regions are greening due to increasing rainfall.

If sustained, these rains could revitalize drought-ravaged regions,

reclaiming them for farming communities. This desert-shrinking

trend is supported by climate models, which predict a return

to conditions that turned the Sahara into a lush savanna some

12,000 years ago.

Hurricanes may become more devastating than Katrina

It has not been determined whether Katrina was linked to

global warming. But there are indications that global warming

will produce more Category 5 hurricanes --and Katrina was

only Category 4 when it hit Louisiana. Hurricanes derive their

power in part from warm water, and so forecasting models

show future hurricanes becoming more severe as sea surface

temperatures rise. Global warming also makes hurricanes more

destructive by raising the sea level, which leads to more

serious coastal flooding. (According to the EPA, a two-foot

rise would swallow a chunk of the U.S. bigger

than Massachusetts.)

London may disappear underwater by 2100

It isn't only reefs and low-lying islands that are under threat

from global warming. In fact, a major threat is for those large

urban areas which are at risk of eventually being submerged

underwater. This is caused by a change in sea levels that

occurs when global warming takes place, resulting in coastal

cities being destroyed by flooding. Dozens of the world's cities,

including London and New York, could be flooded by the end

of the century, according to research which suggests that global

warming will increase sea levels more rapidly than was previously

thought. London is one of the major world capitals at high risk

of this type of flooding, as depicted in this shot from the 2007

movie Flood. Scientists say that the city could be under water

as early as within the next one hundred years.

Animals may shrink

Warming climate may favor small species over large ones.

The research, based on analysis of body mass of fish, plankton,

and bacteria in European ecosystems, comes just weeks after

scientists reported that sheep on a Scottish island are shrinking

due to warmer conditions.

The new study reveals that individual species lost an average of
50 percent of their body mass over the past 30 years. The reduced
body size is the third universal ecological response to global
warming. An earlier sheep study suggested that shorter and
milder winters mean lambs do not need to put on as much as
weight as they once did in order to survive their first year of life,
a factor that could also impact fish populations. Nonetheless the
researchers say the shift could alter food chains, with apex
predators being particularly affected by shrinking prey.

2,000 Indonesian islands may disappear

At least 2,000 small islands across archipelagic Indonesia may

disappear by 2030 as a consequence of excessive mining and

other environment-damaging activities. Indonesia has already

lost 24 of its more than 17,500 islands.

Global warming may increase terrorism

Global warming could destabilize "struggling and poor" countries

around the world, prompting mass migrations and creating 

breeding grounds for terrorists. People are likely to flee 

destabilized countries, and some may turn to terrorism. 

The conditions exacerbated by the effects of climate change

could increase the pool of potential recruits into terrorist activity.

According to the chairman of the National Intelligence Council

in the US, economy refugees will perceive additional reasons 

to flee their homes because of harsher climates. That will put

pressure on countries receiving refugees, many of which 

will have neither the resources nor interest to host these

climate migrants.

The Alps may melt completely

Glaciers are retreating in warm, dry winters and hotter summers

caused by global warming, and although snowfall in the 

2008-2009 ski seasons was substantial, overall recent years 

have seen less snow at low altitudes, and receding glaciers 

and melting permafrost higher up - with a significant impact 

on winter tourism activities. It is predicted that the glaciers 

will be gone between 2030 and 2050. Italy and Switzerland 

have decided to redraw their border after global warming

dissolved Alpine glaciers that marked out the frontier between 

the two countries.

The Maldives may be submerged

The lowest and flattest country in the world is suffering coastal 

erosion, and could find itself submerged if sea levels carry on

rising, with the islands growing smaller and smaller. This extreme

prediction is a devastating prospect for residents and bad news

for the tourists who descend on its soft white beaches and 

warm waters each year. Scientists give it only about one 

hundred years before it completely disappears into the 

ocean surrounding it.