b.a#13
10. Pluto-Sized Eris Rocks Solar System
In January 2005, Mike Brown and his team at Palomar
Observatory, Calif. discovered 136199 Eris, a minor body that is 27 percent
bigger than Pluto. Eris had trumped Pluto and become the 9th largest body known
to orbit the sun.
In 2006, the International Astronomical Union (IAU) decided
that the likelihood of finding more small rocky bodies in the outer solar
system was so high that the definition "a planet" needed to be
reconsidered. The end result: Pluto was reclassified as a dwarf planet. Pluto
acquired a "minor planet designator" in front of its name:
"134340 Pluto."
Mike Brown's 2005 discovery of Eris was the trigger that
changed the face of our solar system, defining the planets and adding Pluto to
a growing family of dwarf planets.
9. T. rex Tissue Dug from Bone
In 2005, Mary Higby Schweitzer and her colleagues reported
in Science the discovery of what appeared to be soft tissues -– blood vessels,
bone matrix and other cells –- inside the fossilized femur of a small T. rex.
Since then, the bones have revealed amino acids that
resemble those of modern chickens, firming the link between dinosaurs and
birds.
Schweitzer's discovery comes in a decade of other stunning
revelations about the soft parts of dinosaurs.
In 2004, one of the few mummified dinosaurs ever found -- an
amazingly well-preserved
66-million-year-old hadrosaur with intact, mostly mineralized
skin -- was excavated from a ranch in North Dakota.
Then, in June 2009, researchers announced they had isolated
molecules related to soft skin tissues from that hadrosaur.
8. Dark Matter's Existence Confirmed Directly
In the summer of 2006, astronomers made an announcement that
helped humans understand the cosmos a little better: They had direct evidence
confirming the existence of dark matter -- even though they still can't say
what exactly the stuff is.
The unprecedented evidence came from the careful weighing of
gas and stars flung about in the head-on smash-up between two great clusters of
galaxies in the Bullet Cluster.
Until then, the existence of dark matter was inferred by the
fact that galaxies have only one-fifth of the visible matter needed to create
the gravity that keeps them intact. So the rest must be invisible to telescopes:
That unseen matter is "dark."
The observations of the Bullet Cluster, officially known as
galaxy cluster 1E0657-56, did not explain what dark matter is. They did,
however, give researchers hints that dark matter particles act a certain way,
which future research can build on.
7. New Human Ancestors Emerge
In 2002, researchers in northern Chad unearthed the 6- to
7-million-year-old skull of Sahelanthropus tchadensis -- known as Toumai. Only
skull bones have been discovered, so it's not confirmed whether Toumai walked
upright on two feet. But other Toumai remains make a stronger case that it
greatly extends the human family timeline.
Then along came Ardi. In 2009, the nearly complete skeleton
of Ardipithecus ramidus, a.k.a. “Ardi,”
in northeastern Ethiopia bumped the famous “Lucy” as the earliest, most
complete skeleton of a human ancestor ever found.
The 4.4-million-year-old Ardi could walk on two legs, but
was also a skilled tree-climber. Her teeth suggest she ate many different types
of food. And scientists theorize that males and females may have paired off at
this time, significantly boosting survival, since females could intensify their
parenting while males provided food.
If the studies prove true, Ardi marks the closest we have
come to discovering the last common ancestor of chimpanzees and humans.
6. Alien Planets Seen Directly
The first alien planets -- called exoplanets -- were being
detected in the early 1990s, but not directly. In 2000, astronomers detected a
handful by looking for a star's "wobble," or a star's slight dimming
as the exoplanet passed in front of it. Today we know of 400 exoplanets.
The Keck observation was the infrared detection of three
exoplanets orbiting a star called HR8799, 150 light-years from Earth. Hubble
spotted one massive exoplanet orbiting the star Fomalhaut, 25 light-years from
Earth.
These finds pose a profound question: How long will it be
until we spot an Earth-like world with an extraterrestrial civilization looking
back at us?
5. Humans Meld with Machines
Cyborgs are becoming reality. In the last decade, much
progress has been made with people controlling robotic limbs and computers with
their minds.
In 2000, researchers at Duke University Medical Center
implanted electrodes in monkeys’ brains and then trained them to reach for food
using a robotic arm. Such a neurochip could one day restore motor function in
paralyzed patients.
A team from the MIT Media Lab Europe developed a
non-invasive method for picking up brain waves and, in 2004, used those signals
for the first time to control the movements of a video game character.
Robotic limbs operated with nerve signals debuted in 2001 at
the Rehabilitation Institute of Chicago. There, Jesse Sullivan, a double
amputee, used the method to control both of his robotic arms.
And in 2009, amputee Pierpaolo Petruzziello learned to
control a biomechanical hand connected to his arm nerves with just wires and
electrodes. Petruzziello became the first person to make complex movements --
finger wiggling, a fist, grabbing objects -- with a robotic limb, using just
his thoughts.
4. Stem Cells Found in New Sources
In 2001, President George W. Bush cut federal funding to
scientists working with embryonic stem cells -- found in a tiny, hollow ball of
about 70-100 human cells that could become anything in the human body --
because of ethical concerns.
Embryonic stem cells were one of the most promising medical
advances in years, with the potential to cure diseases from diabetes to cancer
to genetic disorders, and more.
In 2007, scientists from Kyoto University and the University
of Wisconsin-Madison, working separately, essentially turned back the clock for
adult skin cells, allowing these mature cells, which were preprogrammed to
become skin, to act like embryonic stem cells. The adult cells became
pluripotent cells, or cells that could end up being virtually any other kind of
cell.
These pluripotent adult cells solved two big problems.
Ethical concerns and financial restrictions could be avoided, and doctors could
ultimately use cells with a person's own DNA to grow replacement organs that a
patient would be less likely to reject.
3. Mars Surface Gives up Signs of Water
In 2008, NASA's Mars Phoenix lander touched down on the Red
Planet to confirm the presence of water and seek out signs of organic
compounds.
Eight years before, the Mars Global Surveyor spotted what
appeared to be gullies carved into the landscape by flowing water. More
recently, the Mars Exploration Rovers have uncovered minerals that also
indicated the presence of ancient water. But proof of modern-day water was elusive.
Then Phoenix, planted on the ground near the North Pole, did
some digging for samples to analyze. During one dig, the onboard cameras
spotted a white powder in the freshly dug soil. In comparison images taken over
the coming days, the powder slowly vanished. After intense analysis, the white
powder was confirmed as water ice.
This discovery not only confirmed the presence of water on
the Red Planet, it reenergized the hope that some kind of microbial life might
be using this water supply to survive.
2. Human Genome Mapped
Coiled up inside every human cell sit 23 molecules that, if
unwound and placed end to end, would stretch about three feet. Those molecules,
known as chromosomes, contain all the instructions necessary to build an entire
human being.
The publicly funded Human Genome Project and its private
competitor, Celera Genomics, constitutes one of the largest scientific
endeavors in history, one that revealed in intimate detail just what makes up a
human being.
With the information from individual genome maps, scientists
can uncover new clues about everything from a person's body odor to mental
disease.
Since decoding the human genome, dozens of other species
have had their genomes sequenced, including pigs, dogs, bees, mosquitoes,
puffer fish, chimpanzees, yeast, corn, and rice. With these maps in hand,
scientists can and will discover new ways to heal diseases or improve crop
yields.
1. Glaciers Melting Fast
When
the 21st century began, scientists studying Earth’s climate thought the
gigantic ice caps on Greenland and Antarctica would melt slowly around the
edges and lag behind the overall global warming of climate.
But this past decade, the warmest on record, proved the climate modelers
wrong.
Glaciers have been melting much faster than ever expected and researchers
have been trying to understand why.
The uptick in melting ice has not been restricted to the
Arctic and Antarctic. Europe’s glaciers are now thought to be
entering their final decades.
The famous snows of Kilimanjaro and other low-latitude mountains could
disappear completely. The thick, perennial sea ice of the Arctic is fast
disappearing, which will likely bring ice-free summers to the Arctic Ocean.
There
are global consequences to this melting. Rising seas will make more cities and
islands vulnerable to catastrophic flooding like that which nearly killed New
Orleans. Mountain glaciers around the world bring fresh water to billions. Any
way you slice it, an Earth with less ice is a less hospitable planet.
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