[clock ticking]
[music playing]
CARL AZUZ: Hi, I'm Carl Azuz, delivering
one of two shows we're producing this week before we go on break
for the Thanksgiving holiday.
Welcome, one and all, to CNN 10.
We start today's show in California's Sierra Nevada
mountain range, the only place on Earth where giant sequoia
trees naturally grow.
And forest scientists say some of these very trees
have been alive for thousands of years.
CLAY JORDAN: Before ancient Rome, before Christ, I mean,
these trees were mature.
CARL AZUZ: One big reason why many have survived that long is
because in the past, they've been
able to withstand the wildfires that are common to this part
of the world.
Their 200-foot-high canopies stretch above the flames.
Their thick bark protects them close to the ground.
And milder fires actually help these trees
reproduce, because the heat causes their cones
to release new seeds.
The problem is, the size and intensity
of some recent wildfires in California
have been overwhelming for thousands
of giant sequoia trees.
SAM HODDER: A giant sequoia that was first weakened by drought
was then subject to impacts by the bark beetle, which then
further weakened the tree and potentially
made it more susceptible to mortality from fire.
CARL AZUZ: Conservationists have seen hope on the forest floor,
with many baby giant sequoias sprouting up in the months
after the fires.
And there are some steps people can
take, from controlled burning of forest vegetation,
to the removal of other trees and brush
to protect the mature sequoias of the Sierra Nevada.
But a conservationist interviewed by CNN
and The Denver Channel says the restoration work that needs
to be done would cost billions.
And in the meantime, the danger remains.
STEPHANIE ELAM: We're on a hike in the Sierra Nevada mountains.
[interposing voices]
But this is a tour of sequoia destruction.
CHRISTY BRIGHAM: I'm not happy about 2,000 to 3,000
more dead, large, sequoias.
It's a big number to me.
STEPHANIE ELAM: That's 3% to 5% of the remaining monarch
sequoias in the world, according to a preliminary report
by the National Park Service, killed in the KNP Complex
Fire that churned through Sequoia
and Kings Canyon National Parks and the Windy
Fire further south.
And that big number is on top of an even larger loss
of mature sequoias last year in the Castle Fire,
part of the Sequoia complex, that wildfire
eviscerating 10% to 14% of the world's
giant sequoia population.
Brigham says this means in just the last two years, up
to a fifth of mature sequoias, trees that have stood
for at least 1,000 years, if not more,
have been lost to wildfire.
It's a conflux of concerns these scientists never thought they
would see, the threat made worse by another year of drought,
leaving the sequoias dry and vulnerable.
GARRETT DICKMAN: That means its water source has been
there for over 2,000 years.
That water is not there means that the climate and the world
around it has changed.
STEPHANIE ELAM: But lessons learned last year helped
save some sequoia this year.
CHRISTY BRIGHAM: Before the Castle Fire,
we had never seen losses of large trees
like we had in that fire, 7,500 to 10,600 large sequoias
lost in a single fire event.
And that really changed what we decided we were willing to do
to protect trees if we could.
STEPHANIE ELAM: And what they were willing to do
called for innovation in the face of fire.
From literally throwing what they could at the threat,
like sprinkler systems that sprayed trees
35 to 40 feet in the air, and dropping fire retardant gel
from aircraft into hard to reach groves,
to extreme tree-hugging, swaddling some of the world's
largest trees, like General Sherman and General Grant,
in structure wrap.
CHRISTY BRIGHAM: We had hand crews going in and doing
this kind of raking and fuel removal
around individual trees and groves.
We did backfiring operations to change fire behavior.
STEPHANIE ELAM: But the loss of any sequoia,
such rare and majestic beauties, is one too many to lose.
CHRISTY BRIGHAM: It is dead.
That tree is dead.
It is not coming back.
This tree that is, at a minimum 1,000 years
old, and has survived many, many, many previous fires,
and should have lived another 1,000 to 2,000 years, is dead,
is gone.
STEPHANIE ELAM: Stephanie Elam, CNN,
the Sierra Nevada Mountains.
CARL AZUZ: 10-second trivia.
What do Hermes, Icarus, and Vesta have in common?
Are they all car models, characters in Greek mythology,
asteroid names, or tire brands?
[beeping]
Vesta was a character in Roman mythology,
but these are all the names of asteroids.
[music playing]
There's another one named Didymos zipping through space.
It has its own tiny moon, what NASA calls
a moonlet, orbiting around it.
And that moonlet will be the target of a new NASA mission.
It's called DART for short.
It includes a spacecraft that's set
to launch sometime between this Tuesday
night and February 15th.
It's scheduled to near Didymos' moonlet next fall.
And after it does, the plan is for a spacecraft
to smash right into it.
Why do this?
The goal, astronomers say, is to nudge the moonlet.
The Planetary Society says if all goes according to plan,
the collision will push the moonlet slightly closer
to Didymos and shorten its orbit around the asteroid
by a few minutes.
You can think of this as a type of high-tech science
experiment taking place almost seven million miles away.
Estimated cost, somewhere around $320,000,000.
Here's why NASA's doing this.
- It's a space story seen several
times in the movies, like in the 1998 sci-fi film "Armageddon."
BRUCE WILLIS: The United States Government just
asked us to save the world.
Anybody want to say no?
- An asteroid threatens Earth.
The military, astronauts, even oil rig drillers,
try to save mankind.
Some cities don't make it, but in the end,
the planet survives, a Hollywood ending which NASA is hoping
to make a reality with its first planetary defense test mission.
Scientists say they have identified
the kilometer-wide asteroids like those shown
in the blockbusters, and there are no dangers of them hitting
Earth in the coming centuries.
But NASA says it wants to study what
could be done if an Earth-threatening
asteroid is discovered.
On Wednesday it will launch a mission called DART, the Double
Asteroid Redirection Test, that will send
an unmanned spacecraft into space and, if successful,
it won't be returning home.
DART is set to launch aboard a SpaceX Falcon 9 rocket
and will travel through space for the next nine months,
its destination a near-earth asteroid
named Didymos and its moonlet.
NANCY CHABOT: These asteroids are not a threat to the Earth.
They are not a danger to the Earth.
They are not on a path to hit the Earth
in the foreseeable future.
That makes them appropriate targets for a first test.
- Traveling at a speed of 6.6 kilometers a second,
DART will then deliberately crash
into the moonlet to try to jolt it from its regular orbit.
Scientists back on Earth will monitor the collision
using satellite imagery and ground-based telescopes
to see how much the moonlet changes course.
ANDY CHENG: If one day an asteroid is discovered
on a collision course with Earth,
then we have an idea of how big the asteroid is,
and how fast it's coming, and when it will hit,
that kind of information.
Then we will have an idea how much momentum we need to make
that asteroid miss the Earth.
- The targeted moonlet is a little larger than one
of the pyramids in Egypt.
NASA says there are 10,000 known asteroids that are just
as big, or bigger, that could potentially cause
major regional damage if they ever
hit the Earth, although none of them are tracking this way.
DART's kamikaze mission could provide
life-saving data, if anything ever does get too close.
[music playing]
CARL AZUZ: A new auction record has just
been set for the most money ever paid for a book, printed text,
or historical document.
And the historical document that set it
is a rare copy of the US Constitution.
The original was handwritten and not for sale.
You can see it at the National Archives in Washington, D.C.
But of the 500 copies that were printed in September of 1787,
just 13 of them are known to survive.
And this one was estimated to fetch
between $15 and $20 million.
However, after a bidding war, the CEO
of an investment company won the auction with a $43.2 million
bid.
He reportedly plans to loan it to a museum.
Not every executive would have the power to spend that.
Not everyone with the money would have the Constitution.
Is the sale a preamble to more auction records?
Those can always be amended and documented,
and this one will be preserved for posterity.
It makes sense, though, that the record would set a record.
It's fitting for one of the oldest
surviving documents of the oldest
surviving governing document.
I'm Carl Azuz.
West Morton High School gets today's shoutout.
It is great to see you, our viewers, in Berwyn, Illinois.
We have one more show to go before we're off
for the Thanksgiving holiday.
[music playing]