While lakeshore property on Mars might sound like the biggest real estate swindle ever, the news of the first definitive lakeshore on Mars is momentous. Using images from the HiRISE Camera on the Mars Reconnaissance Orbiter, a University of Colorado at Boulder research team has discovered indications of a deep, ancient lake, estimated to be more than 3 billion years old.

The lake appears to have covered as much as 80 square miles and was up to 460 meters (1,500 feet) deep — roughly the equivalent of Lake Champlain bordering the United States and Canada, said CU-Boulder Research Associate Gaetano Di Achille, who led the study. The shoreline evidence, found along a broad delta in a region called Shalbatana Vallis, includes a series of alternating ridges and troughs thought to be surviving remnants of beach deposits.

“This is the first unambiguous evidence of shorelines on the surface of Mars,” said Di Achille. “The identification of the shorelines and accompanying geological evidence allows us to calculate the size and volume of the lake, which appears to have formed about 3.4 billion years ago.”

An analysis of the HiRISE images indicate that water carved a 50 km (30 mile) -long canyon that opened up into a valley, depositing sediment that formed a large delta. This delta and others surrounding the basin imply the existence of a large, long-lived lake, said team member Brian Hynek, also from CU-Boulder.
“Finding shorelines is a Holy Grail of sorts to us,” said Hynek.

In addition, the evidence shows the lake existed during a time when Mars is generally believed to have been cold and dry, which is at odds with current theories proposed by many planetary scientists, he said. “Not only does this research prove there was a long-lived lake system on Mars, but we can see that the lake formed after the warm, wet period is thought to have dissipated.”

Planetary scientists think the oldest surfaces on Mars formed during the wet and warm Noachan epoch from about 4.1 billion to 3.7 billion years ago that featured a bombardment of large meteors and extensive flooding. The newly discovered lake is believed to have formed during the Hesperian epoch and postdates the end of the warm and wet period on Mars by 300 million years, according to the study.

The deltas adjacent to the lake are of high interest to planetary scientists because deltas on Earth rapidly bury organic carbon and other biomarkers of life, according to Hynek. Most astrobiologists believe any present indications of life on Mars will be discovered in the form of subterranean microorganisms.

But in the past, lakes on Mars would have provided cozy surface habitats rich in nutrients for such microbes, Hynek said.

The retreat of the lake apparently was rapid enough to prevent the formation of additional, lower shorelines, said Di Achille. The lake probably either evaporated or froze over with the ice slowly turning to water vapor and disappearing during a period of abrupt climate change, according to the study.

Di Achille said the newly discovered pristine lake bed and delta deposits would be would be a prime target for a future landing mission to Mars in search of evidence of past life.

“On Earth, deltas and lakes are excellent collectors and preservers of signs of past life,” said Di Achille. “If life ever arose on Mars, deltas may be the key to unlocking Mars’ biological past.”

The team’s paper has been published online in Geophysical Research Letters, a publication of the American Geophysical Union.

Astronomers use the terms “solar radius” and “solar mass” to compare large and smaller stars, so we’ll do the same. A solar radius is 690,000 km (432,000 miles) and a solar mass is 2 x 1030 kilograms (4.3 x 1030 pounds). That’s 2,000,000,000,000,000,000,000,000,000,000 kg.

One huge, famous star in our galaxy is the monster Eta Carinae, located approximately 7,500 light years away, and weighing in at 100 solar masses. It’s 4 million times as bright as the Sun. Most stars blow with a solar wind, losing mass over time. But Eta Carinae is so large that it casts off 500 times the mass of the Earth every year. With so much mass lost, it’s very difficult for astronomers to accurately measure where the star ends, and its stellar wind begins.

So the best answer astronomers have right now is that Eta Carinae’s radius is 400 times the size of the Sun. And as star size estimates go, that’s pretty accurate.

And one interesting side note: Eta Carinae should explode pretty soon as one of the most spectacular supernovae humans have ever seen.

But that’s nothing. The largest known star is VY Canis Majoris; a red hypergiant star in the constellation Canis Major, located about 5,000 light-years from Earth. University of Minnesota professor Roberta Humphreys recently calculated its upper size at more than 2,100 times the size of the Sun. Placed in our Solar System, its surface would extend out past the orbit of Saturn. Light takes more than 8 hours to cross its circumference!

Some astronomers disagree, and think that VY Canis Majoris might be smaller; merely 600 times the size of the Sun, extending past the orbit of Mars.

That’s the biggest star that we know of, but the Milky way probably has dozens of stars that are even larger, obscured by gas and dust so we can’t see them.

But let’s see if we can work out the original question, what’s the biggest star in the Universe? Obviously, it’s impossible for us to actually find it – the Universe is a big place, and there’s no way we can peer into every corner.

But according to theorists, how big can stars get?

I contacted Roberta Humphreys from the University of Minnesota, the researcher who calculated the size of VY Canis Majoris, and posed this question to her. She noted that the largest stars are the coolest. So even though Eta Carinae is the most luminous star we know of, it’s extremely hot – 25,000 Kelvin – and so only a mere 400 solar radii.

The largest stars will be the cool supergiants. For example, VY Canis Majoris is only 3,500 Kelvin. A really big star would be even cooler. At 3,000 Kelvin, a cool supergiant would be 2,600 times the size of the Sun.

That, she believes, is the largest possible star.

Finally, here’s a great animation that shows the size of various objects in space, starting with our tiny planet and finally getting to VV Cephei A. I guess they didn’t have the new info on VY Canis Majoris to include it in the animation.

So what is all this crazy talk? We’ve all heard these doomsday predictions before, we’re still here, and the planet is still here, why is 2012 so important? Well, the Mayan calendar stops at the end of the year 2012, churning up all sorts of religious, scientific, astrological and historic reasons why this calendar foretells the end of life as we know it. The Mayan Prophecy is gaining strength and appears to be worrying people in all areas of society. Forget Nostradamus, forget the Y2K bug, forget the credit crunch, this event is predicted to be huge and many wholeheartedly believe this is going to happen for real. Planet X could even be making a comeback.
For all those 2012 Mayan Prophecy believers out there, I have bad news. There is going to be no doomsday event in 2012, and here’s why…

The Mayan Calendar
So what is the Mayan Calendar? The calendar was constructed by an advanced civilization called the Mayans around 250-900 AD. Evidence for the Maya empire stretches around most parts of the southern states of Mexico and reaches down to the current geological locations of Guatemala, Belize, El Salvador and some of Honduras. The people living in Mayan society exhibited very advanced written skills and had an amazing ability when constructing cities and urban planning. The Mayans are probably most famous for their pyramids and other intricate and grand buildings. The people of Maya had a huge impact on Central American culture, not just within their civilization, but with other indigenous populations in the region. Significant numbers of Mayans still live today, continuing their age-old traditions.

The Mayans used many different calendars and viewed time as a meshing of spiritual cycles. While the calendars had practical uses, such as social, agricultural, commercial and administrative tasks, there was a very heavy religious element. Each day had a patron spirit, signifying that each day had specific use. This contrasts greatly with our modern Gregorian calendar which primarily sets the administrative, social and economic dates.

Most of the Mayan calendars were short. The Tzolk’in calendar lasted for 260 days and the Haab’ approximated the solar year of 365 days. The Mayans then combined both the Tzolk’in and the Haab’ to form the “Calendar Round”, a cycle lasting 52 Haab’s (around 52 years, or the approximate length of a generation). Within the Calendar Round were the trecena (13 day cycle) and the veintena (20 day cycle). Obviously, this system would only be of use when considering the 18,980 unique days over the course of 52 years. In addition to these systems, the Mayans also had the “Venus Cycle”. Being keen and highly accurate astronomers they formed a calendar based on the location of Venus in the night sky. It’s also possible they did the same with the other planets in the Solar System.

Using the Calendar Round is great if you simply wanted to remember the date of your birthday or significant religious periods, but what about recording history? There was no way to record a date older than 52 years.

The end of the Long Count = the end of the Earth?
The Mayans had a solution. Using an innovative method, they were able to expand on the 52 year Calendar Round. Up to this point, the Mayan Calendar may have sounded a little archaic – after all, it was possibly based on religious belief, the menstrual cycle, mathematical calculations using the numbers 13 and 20 as the base units and a heavy mix of astrological myth. The only principal correlation with the modern calendar is the Haab’ that recognised there were 365 days in one solar year (it’s not clear whether the Mayans accounted for leap years). The answer to a longer calendar could be found in the “Long Count”, a calendar lasting 5126 years.

I’m personally very impressed with this dating system. For starters, it is numerically predictable and it can accurately pinpoint historical dates. However, it depends on a base unit of 20 (where modern calendars use a base unit of 10). So how does this work?

The base year for the Mayan Long Count starts at “0.0.0.0.0″. Each zero goes from 0-19 and each represent a tally of Mayan days. So, for example, the first day in the Long Count is denoted as 0.0.0.0.1. On the 19th day we’ll have 0.0.0.0.19, on the 20th day it goes up one level and we’ll have 0.0.0.1.0. This count continues until 0.0.1.0.0 (about one year), 0.1.0.0.0 (about 20 years) and 1.0.0.0.0 (about 400 years). Therefore, if I pick an arbitrary date of 2.10.12.7.1, this represents the Mayan date of approximately 1012 years, 7 months and 1 day.

This is all very interesting, but what has this got to do with the end of the world? The Mayan Prophecy is wholly based on the assumption that something bad is going to happen when the Mayan Long Count calendar runs out. Experts are divided as to when the Long Count ends, but as the Maya used the numbers of 13 and 20 at the root of their numerical systems, the last day could occur on 13.0.0.0.0. When does this happen? Well, 13.0.0.0.0 represents 5126 years and the Long Count started on 0.0.0.0.0, which corresponds to the modern date of August 11th 3114 BC. Have you seen the problem yet? The Mayan Long Count ends 5126 years later on December 21st, 2012.

Doomsday
When something ends (even something as innocent as an ancient calendar), people seem to think up the most extreme possibilities for the end of civilization as we know it. A brief scan of the internet will pull up the most popular to some very weird ways that we will, with little logical thought, be wiped off the face of the planet. Archaeologists and mythologists on the other hand believe that the Mayans predicted an age of enlightenment when 13.0.0.0.0 comes around; there isn’t actually much evidence to suggest doomsday will strike. If anything, the Mayans predict a religious miracle, not anything sinister.

Myths are abound and seem to be fuelling movie storylines. It looks like the new Indiana Jones and the Kingdom of the Crystal Skull is even based around the Mayan myth that 13 crystal skulls can save humanity from certain doom. This myth says that if the 13 ancient skulls are not brought together at the right time, the Earth will be knocked off its axis. This might be a great plotline for blockbuster movies, but it also highlights the hype that can be stirred, lighting up religious, scientific and not-so-scientific ideas that the world is doomed.

Some of the most popular space-based threats to the Earth and mankind focus on Planet X wiping most life off the planet, meteorite impacts, black holes, killer solar flares, Gamma Ray Bursts from star systems, a rapid ice age and a polar (magnetic) shift. There is so much evidence against these things happening in 2012, it’s shocking just how much of a following they have generated. Each of the above “threats” needs their own devoted article as to why there is no hard evidence to support the hype.

But the fact remains, the Mayan Doomsday Prophecy is purely based on a calendar which we believe hasn’t been designed to calculate dates beyond 2012. Mayan archaeo-astronomers are even in debate as to whether the Long Count is designed to be reset to 0.0.0.0.0 after 13.0.0.0.0, or whether the calendar simply continues to 20.0.0.0.0 (approximately 8000 AD) and then reset. As Karl Kruszelnicki brilliantly writes:

“…when a calendar comes to the end of a cycle, it just rolls over into the next cycle. In our Western society, every year 31 December is followed, not by the End of the World, but by 1 January. So 13.0.0.0.0 in the Mayan calendar will be followed by 0.0.0.0.1 – or good-ol’ 22 December 2012, with only a few shopping days left to Christmas.”

Officials said more than 50 people were injured in the explosions at the Ritz-Carlton and JW Marriott hotels, which punched out the windows of a usually crowded restaurant and sent plumes of smoke into the sky.

President Susilo Bambang Yudhoyono said the bombings as the work of extremists.

“I condemn this terrorist attack,” Yudhoyono said. “I know they will never stop.”

One hospital reported that there were 16 foreigners wounded in the blast, according to state-run Antara News Agency. The victims were from the United States, Italy, South Korea, Japan, Norway, Netherlands, India, Australia and Britain.

Indonesia has been hit by several deadly bomb attacks targeting foreigners in recent years. More than 200 people were killed on the resort island of Bali in 2002 while 12 people were killed in a blast at the same Marriott hotel in Jakarta in 2003.

Those attacks were blamed on the Jemaah Islamiyah terror group, said to have links to Al-Qaeda.

Presidential spokesman Dino Patti Djalal said the attacks on the hotels, which stand 50 meters apart, were coordinated.

Forensics experts are collecting evidence at the “disturbing scene,” Djalal said. He said he had few details about the blasts, which occurred about 7:48 a.m. (8:48 p.m. Thursday ET) on Friday, Islam’s holy day.

Later Friday, police confirmed they had found an unexploded bomb in a room on the 18th floor of the Marriott Hotel.

“We had to defuse the bomb because it’s armed and ready to explode. The bomb is now secure,” a police spokesman said.

Djalal, who said the lobby of the Marriott bore the brunt of the explosions, vowed that those behind the attacks would be brought to justice.

“What I can say is one of the most damaged areas that we looked at, where the bodies were, was a lounge area in the Marriott near the lobby,” Djalal said. “That seems to be the epicenter of the bomb.”

“This is a blow to us, but I don’t have any doubts that we will be able to uncover and find out the perpetrators,” he said.

No one has claimed responsibility for the attacks.

Police said the bomb at the Marriott likely came from the basement beneath the coffee shop on the ground floor, which would have been busy at breakfast time.