Earth Archives

October 11, 2013December 23, 2015 by Ken Kremer

NASA’s Juno Spacecraft Returns 1st Flyby images of Earth while Sailing On to Jupiter

Juno swoops over Argentina This reconstructed day side image of Earth is one of the 1st snapshots transmitted back home by NASA’s Jupiter-bound Juno spacecraft during its speed boosting flyby on Oct. 9, 2013. It was taken by the probes Junocam imager and methane filter at 12:06:30 PDT and an exposure time of 3.2 milliseconds. Juno was flying over South America and the southern Atlantic Ocean. The coastline of Argentina is visible at top right. Credit: NASA/JPL/SwRI/MSSS/Ken Kremer

Following the speed boosting slingshot of Earth on Wednesday, Oct. 9, that sent NASA’s Juno orbiter hurtling towards Jupiter, the probe has successfully transmitted back data and the very first flyby images despite unexpectedly going into ‘safe mode’ during the critical maneuver.

“Juno is transmitting telemetry today,” spokesman Guy Webster, of NASA’s Jet Propulsion Lab (JPL), told me in a phone interview late today (Oct. 10), as Juno continues sailing on its 2.8 Billion kilometer (1.7 Billion mile) outbound trek to the Jovian system.

The new images of Earth captured by the Junocam imager serves as tangible proof that Juno is communicating.

“Juno is still in safe mode today (Oct. 10),” Webster told Universe Today.

“Teams at mission control at JPL and Lockheed Martin are actively working to bring Juno out of safe mode. And that could still require a few days,” Webster explained.

Lockheed Martin is the prime contractor for Juno.

The initial raw images of Earth snapped by the craft’s Junocam imager were received by ground stations late today.

See above a day light image mosaic which I reconstructed and realigned based on the original raw image (see below) taken with the camera’s methane filter on Oct. 9 at 12:06:30 PDT (3:06:30 PM EST). Juno was to be flying over South America and the southern Atlantic Ocean.

This day side raw image of Earth is one of the 1st snapshots transmitted back home today by NASA’s Juno spacecraft during its speed boosting flyby on Oct. 9, 2013. It was taken by the probes Junocam imager and methane filter at 12:06:30 PDT and an exposure time of 3.2 ms. Credit: NASA/JPL/SwRI/MSSS — This day side raw image of Earth is one of the 1st snapshots transmitted back home today by NASA’s Juno spacecraft during its speed boosting flyby on Oct. 9, 2013. It was taken by the probes Junocam imager and methane filter at 12:06:30 PDT and an exposure time of 3.2 milliseconds. Juno was due to be flying over South America and the southern Atlantic Ocean. Credit: NASA/JPL/SwRI/MSSS

Juno performed a crucial swingby of Earth on Wednesday that accelerated the probe by 16330 MPH to enable it to arrive in orbit around Jupiter on July 4, 2016.

However the gravity assist maneuver did not go entirely as planned.

Shortly after Wednesday’s flyby, Juno Project manager Rick Nybakken, of JPL, told me in a phone interview that Juno had entered safe mode but that the probe was “power positive and we have full command ability.”

“After Juno passed the period of Earth flyby closest approach at 12:21 PM PST [3:21 PM EDT] and we established communications 25 minutes later, we were in safe mode,” Nybakken explained.

The safe mode was triggered while Juno was in an eclipse mode, the only eclipse it will experience during its entire mission.

The Earth flyby did accomplish its objective by placing the $1.1 Billion Juno spacecraft exactly on course for Jupiter as intended.

“We are on our way to Jupiter as planned!”

“None of this affected our trajectory or the gravity assist maneuver – which is what the Earth flyby is,” Nybakken stated.

Juno’s closest approach was over South Africa at about 561 kilometers (349 miles).

Juno’s flight track above Earth during Oct. 9, 2013 flyby. Credit: NASA/JPL

During the flyby, the science team also planned to observe Earth using most of Juno’s nine science instruments since the slingshot also serves as a key test of the spacecraft systems and the flight operations teams.

Juno also was to capture an unprecedented new movie of the Earth/Moon system.

Many more images were snapped and should be transmitted in coming days that eventually will show a beautiful view of the Earth and Moon from space.

“During the earth flyby we have most of our instruments on and will obtain a unique movie of the Earth Moon system on our approach, Juno principal investigator Scott Bolton told me. Bolton is from the Southwest Research Institute (SwRI), San Antonio, Texas.

“We will also calibrate instuments and measure earth’s magnetosphere, obtain closeup images of the Earth and the Moon in UV [ultraviolet] and IR [infrared],” Bolton explained to Universe Today.

Juno is approaching the Earth from deep space, from the sunlit side.

“Juno will take never-before-seen images of the Earth-moon system, giving us a chance to see what we look like from Mars or Jupiter’” says Bolton.

Here is a description of Junocam from the developer – Malin Space Science Systems

“Like previous MSSS cameras (e.g., Mars Reconnaissance Orbiter’s Mars Color Imager) Junocam is a “pushframe” imager. The detector has multiple filter strips, each with a different bandpass, bonded directly to its photoactive surface. Each strip extends the entire width of the detector, but only a fraction of its height; Junocam’s filter strips are 1600 pixels wide and about 155 rows high. The filter strips are scanned across the target by spacecraft rotation. At the nominal spin rate of 2 RPM, frames are acquired about every 400 milliseconds. Junocam has four filters: three visible (red/green/blue) and a narrowband “methane” filter centered at about 890 nm.”

Juno soars skyward to Jupiter on Aug. 5, 2011 from launch pad 41 at Cape Canaveral Air Force Station at 12:25 p.m. EDT. View from the VAB roof. Credit: Ken Kremer/kenkremer.com

Juno launched atop an Atlas V rocket two years ago from Cape Canaveral Air Force Station, FL, on Aug. 5, 2011 on a journey to discover the genesis of Jupiter hidden deep inside the planet’s interior.

During a one year long science mission – entailing 33 orbits lasting 11 days each – the probe will plunge to within about 3000 miles of the turbulent cloud tops and collect unprecedented new data that will unveil the hidden inner secrets of Jupiter’s origin and evolution.

NBC News has also featured this Juno story – here

Read more about Juno’s flyby in my articles – here and here

Stay tuned here for continuing Juno, LADEE, MAVEN and more up-to-date NASA news.

Ken Kremer

October 10, 2013April 26, 2016 by Shannon Hall

Earth and Climate: Two Scenarios of Our Planet in 2100 AD

The Earth at night. What will it look like 100 years from now? Image credit: NASA-NOAA

The Earth is warming up.

Ocean temperatures are rising. Arctic sea ice is melting. Atmospheric carbon dioxide levels are growing. The oceans are becoming more acidic. The weather is already more extreme.

With the release of the fifth Assessment Report by the Intergovernmental Panel on Climate Change – a panel of more than 2,500 experts, more commonly known as the IPCC – it’s clear that climate change is very real. But it’s especially clear that we are the cause. If we don’t act now by taking vigorous action to reduce emissions the results will be catastrophic.

Toward the end of this 900-page report, the IPCC looked toward our future, focusing on the climate after the year 2100. Here, Universe Today, explores two extreme scenarios for the Earth by 2100.

1.) Embracing the Challenges of Climate Change

The conclusions reached by climate scientists at the end of the 21st Century were undeniable. We embraced climate change by investing heavily in renewable energies. Both large-scale companies and individuals bought energy drawn from the sunlight, wind, and geothermal heat.

Homes across the world became more sustainable. Their total square feet shrunk, as home owners learned to live with less. It was not uncommon to dress a roof with plants or solar panels. Even the layout of homes changed. They rested partially underground, taking advantage of geothermal heat, and faced South (in the case of the Northern hemisphere) to take advantage of the warm sunlight.

We also embraced geoengineering technologies. We added artificial clouds to our atmosphere, which reflected sunlight, and built towers to collect greenhouse gas emissions. The gases are now trapped deep underground. Our goal was not only to slow the process of climate change, but to stop it, and quite possibly reverse it.

We now eat far less meat than we did in the early 21st Century to cut the emissions generated from livestock farming. Pastures have been replaced with booming forests – helping to absorb CO2. We also eat more locally.

The world followed in China’s footsteps and restricted couples to a certain number of children, reducing our overall population.

We live in small compact cities where we drive hybrid cars and take public transport to work. Carbon offsets must be purchased when taking long trips. Most families vacation in their own backyard – exploring all that nature has to offer in the nearby vicinity.

We viewed climate change as an exciting opportunity to embrace the needs of our environment. We now live much simpler lives and the census shows that our overall intelligence and happiness is much higher than it was a century ago.

2.) The Point of No Return

We simply didn’t want to face the facts. We live in a global economy with a population that has increased significantly over the last century. Most of our energy still comes from fossil fuels. We never invested in renewable energies.

We measure our happiness based on the cars we drive, the number of material possessions we can cram into our large homes, and how often we travel the globe.

The world is, on average, 9 degrees warmer. The entire arctic has melted. Ocean levels have risen by over a meter – flooding coastal communities across the world. Millions have been left homeless.

Our weather is extreme. Hurricanes, tornadoes, fires, floods, draughts, and earthquakes kill hundreds of thousands per year. Climate change has devastated food production and water supplies.

Air quality is much poorer across the world. Due to haze, it is perfectly safe to look at the sun directly. We can only see a third of the stars visible a century ago.

We have triggered various tipping points. The thawing of permafrost released further CO2 and methane. Large areas of the planet are becoming uninhabitable. Our efforts are working toward damage control only. We fear that it may be too late.

Climate change is still in our hands, but we have to act now.

The fifth Assessment Report by the IPCC may be found here. Emphasis in this article may be found in the long term climate change section, as well as descriptions published by the IPCC in 2000.

October 9, 2013December 23, 2015 by Ken Kremer

NASA’s Juno probe Gets Gravity Speed Boost during Earth Flyby But Enters ‘Safe Mode’

The first color reconstruction of the Moon by Adam Hurcewicz

Developing story – NASA’s Juno-bound Jupiter orbiter successfully blazed past Earth this afternoon (Oct. 9) and gained its huge and critical gravity assisted speed boost that’s absolutely essential to reach the Jovian system in 2016.

However, Juno’s project manager Rick Nybakken told me moments ago that the Juno spacecraft unexpectedly entered ‘safe mode’ during the fly by maneuver and the mission teams are assessing the situation.

But the very good news is “Juno is power positive at this time. And we have full command ability,” said Nybakken in an exclusive phone interview with me.

“After Juno passed the period of Earth flyby closest approach at 12:21 PM PST [3:21 PM EDT] and we established communications 25 minutes later, we were in safe mode,” Nybakken told me. Nybakken is the Juno mission project manager at NASA’s Jet Propulsion Lab in Pasadena, CA.

Furthermore, the Earth flyby did place the $1.1 Billion Juno spacecraft exactly on course for Jupiter as intended.

“We are on our way to Jupiter as planned!”

“None of this affected our trajectory or the gravity assist maneuver – which is what the Earth flyby is.”

Juno’s closest approach was over South Africa at about 500 kilometers (350 miles).

“Juno hit the target corridor within 2 km of the aim point,” Nybakken elaborated to Universe Today.

Juno needs the 16,330 mph velocity boost from the Earth swingby because the Atlas V launcher was not powerful enough to hurtle the 8000 pound (3267 kg) craft fast enough on a direct path to Jupiter.

And the team is in full radio contact with the probe. Safe mode is a designated protective state.

“Prior to the eclipse, which was a few minutes earlier than closest approach, the spacecraft was ‘nominal’. When we came out of the eclipse Juno was in safe mode,” Nybakken stated.

“We are going through safe mode diagnostics steps right now.”

“We have established full uplink and downlink. And we have full command ability of the spacecraft.”

First JunoCam image of the day! Taken at 11:07 UTC when Juno was 206,000 Kilometers from the Moon.

Speed boosting slingshots have been used on numerous planetary missions in the past

The spacecraft’s power situation and health is as good as can be expected.

“Juno is power positive at this time and sun pointed and stable. So we are very pleased about that,” Nybakken explained.

I asked if Juno had ever entered ‘safe mode’ before?

“We have never been in safe mode before. We are in a safe, stable state.”

“We are investigating this,” said Nybakken.

Today’s (Oct. 9) Earth flyby is the only time the spacecraft experiences an eclipse period during Juno’s entire five year and 1.7 Billion mile (2.8 Billion km) trek to Jupiter, the largest planet in our solar system.

When it finally arrives at Jupiter on July 4, 2016, Juno will become the first polar orbiting spacecraft at the gas giant.

NASA’s Juno spacecraft blasted off atop an Atlas V rocket two years ago from Cape Canaveral Air Force Station, FL, on Aug. 5, 2011 on a journey to discover the genesis of Jupiter hidden deep inside the planet’s interior.

Juno soars skyward to Jupiter on Aug. 5, 2013 from launch pad 41 at Cape Canaveral Air Force Station at 12:25 p.m. EDT. View from the VAB roof. Credit: Ken Kremer/kenkremer.com — Juno soars skyward to Jupiter on Aug. 5, 2011 from launch pad 41 at Cape Canaveral Air Force Station at 12:25 p.m. EDT. View from the VAB roof. Credit: Ken Kremer/kenkremer.com

The science team had also hoped to use the on board JunoCam imager to make a cool and unprecedented movie of Earth as it approached from the sunlit side – showing the passage as though you were a visitor from outer space.

I had an inkling that something might be amiss this afternoon when no images of Earth appeared on the Juno mission website.

So I asked the status.

“We don’t know yet if any images of Earth were collected. We hope to know soon.”

Juno flew past the Moon before the gravity assist slingshot with Earth. And it did manage to successfully capture several lunar images. See the images herein.

Read more about Juno in my flyby preview story – here.

Note: Due to the continuing chaos resulting from the US government partial shutdown caused by gridlocked politico’s in Washington DC, NASA public affairs remains shut down and is issuing no official announcements on virtually anything related to NASA! This pertains to Juno’s flyby, LADEE’s lunar arrival on Oct. 6, MAVEN’s upcoming launch in November, Cygnus at the ISS, and more!

Stay tuned here for continuing Juno, LADEE, MAVEN and more up-to-date NASA news.

Ken Kremer

NASA’s Juno Jupiter-bound space probe will fly by Earth for essential speed boost on Oct 9, 2013. Credit: NASA/JPL

October 8, 2013December 23, 2015 by Ken Kremer

Juno Careening to Earth for Critical Flyby Boost and Cool Movie Making on Oct. 9 – Watch SLOOH Live

Trajectory Map of Juno’s Earth Flyby on Oct. 9, 2013
The Earth gravity assist is required to accelerate Juno’s arrival at Jupiter on July 4, 2016 and will capture an unprecedented movie of the Earth/Moon system. Credit: NASA/JPL
Details on how to watch via Slooh – see below [/caption]

NASA’s solar powered Jupiter-bound Juno orbiter is careening towards Earth for an absolutely critical gravity assisted fly by speed boost while capturing an unprecedented movie view of the Earth/Moon system – on its ultimate quest to unveiling Jupiter’s genesis!

“Juno will flyby Earth on October 9 to get a gravity boost and increase its speed in orbit around the Sun so that it can reach Jupiter on July 4, 2016,” Juno chief scientist Dr. Scott Bolton told Universe Today in an exclusive new Juno mission update – as the clock is ticking to zero hour. “The closest approach is over South Africa.”

All this ‘high frontier’ action comes amidst the utterly chaotic US government partial shutdown, that threatened the launch of the MAVEN Mars orbiter, has halted activity on many other NASA projects and stopped public announcements of the safe arrival of NASA’s LADEE lunar orbiter on Oct. 6, Juno’s flyby and virtually everything else related to NASA!

Bolton confirmed that the shutdown fortunately hasn’t altered or killed Juno’s flyby objectives. And ops teams at prime contractor Lockheed Martin have rehearsed and all set.

And some more good news is that Slooh will track the Juno Earth Flyby “LIVE” – for those hoping to follow along. Complete details below!

“The shutdown hasn’t affected our operations or plans, Bolton told me. Bolton is Juno’s principal investigator from the Southwest Research Institute (SwRI), San Antonio, Texas.

“Juno is 100% healthy.”

“But NASA is unable to participate in our public affairs and press activities,” Bolton elaborated.

97% of NASA’s employees are furloughed – including public affairs – due to the legal requirements of the shutdown!

Juno will also capture an unprecedented new movie of the Earth/Moon system.

A full up science investigation of our Home Planet by Juno is planned, that will also serve as a key test of the spacecraft and its bevy of state of the art instruments.

“During the earth flyby we have most of our instruments on and will obtain a unique movie of the Earth Moon system on our approach.

“We will also calibrate instuments and measure earth’s magnetosphere, obtain closeup images of the Earth and the Moon in UV [ultraviolet] and IR [infrared],” Bolton explained to Universe Today.

The flyby will accelerate the spacecraft’s velocity by 16,330 mph.

Where is the best view of Juno’s flyby, I asked?

“The closest approach is over South Africa and is about 500 kilometers [350 miles],” Bolton replied.

The time of closest approach is 3:21 p.m. EDT (12:21 PDT / 19:21 UTC) on Oct. 9, 2013

Watch this mission produced video about Juno and the Earth flyby:

Video caption: On Oct. 9, 2013, NASA’s Jupiter-bound Juno spacecraft is making a quick pass to get a gravity boost from the mother planet. Dr. Scott Bolton of Southwest Research Institute® is the Juno mission principal investigator, leading an international science team seeking to answer some fundamental questions about the gas giant and, in turn, about the processes that led to formation of our solar system.

NASA’s Juno spacecraft blasted off atop an Atlas V rocket two years ago from Cape Canaveral Air Force Station, FL, on Aug. 5, 2011 to begin a 2.8 billion kilometer science trek to discover the genesis of Jupiter hidden deep inside the planet’s interior.

Juno is on a 5 year and 1.7 Billion mile (2.8 Billion km) trek to the largest planet in our solar system. When it arrives at Jupiter on July 4, 2016, Juno will become the first polar orbiting spacecraft at the gas giant.

During a one year science mission – entailing 33 orbits lasting 11 days each – the probe will plunge to within about 3000 miles of the turbulent cloud tops and collect unprecedented new data that will unveil the hidden inner secrets of Jupiter’s genesis and evolution.

The goal is to find out more about the planets origins, interior structure and atmosphere, observe the aurora, map the intense magnetic field and investigate the existence of a solid planetary core

Why does Juno need a speed boost from Earth?

“A direct mission to Jupiter would have required about 50 percent more fuel than we loaded,” said Tim Gasparrini, Juno program manager for Lockheed Martin Space Systems, in a statement.

“Had we not chosen to do the flyby, the mission would have required a bigger launch vehicle, a larger spacecraft and would have been more expensive.”

Viewers near Cape Town, South Africa will have the best opportunity to view the spacecraft traveling across the sky.

Juno itself will most likely not be visible to the unaided eye, but binoculars or a small telescope with a wide field should provide an opportunity to view, according to a Slooh statement.

Slooh will track Juno live on October 9th, 2013.

Check here for international starting times: http://goo.gl/7ducFs – and for the Slooh broadcast hosted by Paul Cox.

Viewers can view the event live on Slooh.com using their computer or mobile device, or by downloading the free Slooh iPad app in the iTunes store. Questions can be asked during the broadcast via Twitter by using the hashtag #nasajuno -says Slooh.

Amidst the government shutdown, Juno prime contractor Lockheed Martin is working diligently to ensure the mission success.

Because there are NO 2nd chances!

“The team is 100 percent focused on executing the Earth flyby successfully,” said Gasparrini.

“We’ve spent a lot of time looking at possible off-nominal conditions. In the presence of a fault, the spacecraft will stay healthy and will perform as planned.”

Stay tuned here for continuing Juno, LADEE, MAVEN and more up-to-date NASA news.

And be sure to check back here for my post-flyby update.

What’s not at all clear is whether Juno will detect any signs of ‘intelligent life’ in Washington D.C.!

Ken Kremer

…………….

Learn more about Juno, LADEE, MAVEN, Curiosity, Mars rovers, Cygnus, Antares, SpaceX, Orion, the Gov’t shutdown and more at Ken’s upcoming presentations

Oct 8: “NASA’s Historic LADEE Lunar & Antares/Cygnus ISS Rocket Launches from Virginia”& “Curiosity, MAVEN, Juno and Orion updates”; Princeton University, Amateur Astronomers Assoc of Princeton (AAAP), Princeton, NJ, 8 PM

October 6, 2013December 23, 2015 by Jason Major

Awesome Photo: Aurora, Airglow, City Lights and Shining Stars

Photo taken by ESA astronaut Luca Parmitano on Sept. 5, 2013 (ESA/NASA)

Italian astronaut Luca Parmitano shares a lot of fantastic photos taken from his privileged position 260 miles up aboard the Space Station, orbiting the planet 16 times a day. This is his latest, a stunning view of nighttime city lights spread out beneath a glowing dome of ghostly airglow and shimmering aurorae, with a backdrop of brightly shining stars. The dark silhouette of a solar array is in the foreground at right.

And in case you were wondering, yes, astronauts certainly can see stars while in space. A lot of them, in fact. (Except up there, they don’t twinkle… but they’re no less beautiful!)

“Every time we look into the sky and we admire the same stars, we share the same experience with all those who still know how to dream.”

– Luca Parmitano

Luca Parmitano is the first of ESA’s new generation of astronauts to fly into space. The current mission, Volare, is ESA’s fifth long-duration Space Station mission. During his six-month-long stay aboard the ISS, Luca has been conducting research for ESA and international partners as well as taken many photographs of our planet, sharing them on Twitter, Flickr, and the Volare mission blog.

See this and more photos taken by Luca on the Volare Flickr page here.

Image credit: ESA/NASA

September 30, 2013December 23, 2015 by Fraser Cain

How Long Will Life Survive on Earth?

A powerful X-class solar flare erupting on the sun on July 6, 2012 photographed by the Solar Dynamics Observers. Credit: NASA

Life has existed on Earth for billions of years, appearing shortly after the planet had cooled and liquid water became available.

From the first bacteria to the amazingly complex animals we see today, life has colonized every corner of our planet.

As you know, our Sun has a limited lifespan.

Over the next 5 billion years, it will burn the last of its hydrogen, bloat up as a red giant and consume Mercury and Venus.

This would be totally disastrous for local flora and fauna, but all life on the surface of the Earth will already be long gone.

In fact, we have less than a billion years to enjoy the surface of our planet before it becomes inhospitable.

Because our Sun… is heating up.

You can’t feel it over the course of a human lifetime, but over hundreds of millions of years, the amount of radiation pouring out of the Sun will grow.

This will heat the surface of our planet to the point that the oceans boil.

At the core of the Sun, the high temperatures and pressures convert hydrogen into helium. For every tonne of material the Sun converts, it shrinks a bit making the Sun denser, and a little hotter.

Over the course of the next billion years or so, the amount of energy the Earth receives from the Sun will increase by about 10%. Which doesn’t sound like much, but it means a greenhouse effect of epic proportions.

A TerraSAR-X stripmap image from 23 April 2009. The larger icebergs are bright, while smaller icebergs are capsized and appear as dark blocks. The inset shows two superimposed Envisat ASAR images from 24 and 27 April. The region outlined in red indicates the area of the TerraSAR-X image. Credits: DLR, ESA (Annotations by A. Humbert, Münster University — A TerraSAR-X stripmap image of icebergs.

Whatever is left of the ice caps will melt, and the water itself will boil away, leaving the planet dry and parched. Water vapor is a powerful greenhouse gas, this will drive the temperatures even hotter.

Plate tectonics will shut down, and all the carbon will be stripped from the atmosphere.

It’ll be bad.

As temperatures rise, complex lifeforms will find life on Earth less hospitable. It will seem as if evolution is running in reverse, as plants and animals die off, leaving the invertebrates and eventually just microbial life.

This rise in temperature will be the end of life on the surface of Earth as we know it.

Still, there are reserves of water deep underground which will continue to protect microbial life for billions of years.

Perhaps they’ll experience that final baking when the Sun does reach the end of its life.

Even a few hundred million years is an incomprehensible amount of time compared to the age of our civilization.

If humanity does survive well into the future, is there anything we could do about this problem?

As the Sun heats up, making Earth inhospitable, it heats up the rest of the Solar System too. Frozen worlds in the Solar System will melt, becoming more habitable.

Encaladus, a moon of Saturn, as shown in this Voyager 1 image. Credit: NASA

It’s possible that future civilizations could relocate to the asteroid belt, or the moons of Saturn. We could try something even more radical: move the Earth.

By carefully steering asteroids so they barely miss us, an advanced civilization could distort the Earth’s orbit, relocating our planet further from the Sun.

As the Sun heats up, our planet would be continuously repositioned so the surface temperature stays roughly the same. Of course, this would be tricky business. Make the wrong move, and you’re facing the frigid cold of the outer Solar System.

So there’s no need to panic. Life here has a few hundred million years left; a billion, tops. But if we want to continue on for billions of years, we’ll want to add solar heating to our growing list of big problems.

September 24, 2013April 26, 2016 by Nancy Atkinson

Electro-L’s Fully Lit View of Planet Earth at the Autumnal Equinox

The entire disk of the Earth lit during the equinox on September 22, 2013. Credit: Roscosmos / NTSOMZ / SRC "Planeta" / zelenyikot.livejournal.com

Here’s a fantastic view of our home planet taken by the Russian weather satellite Electro-L. And while Elektro-L can take gigantic photographs of the entire planet every 30 minutes, it only can get a fully-lit view like this just twice a year — at the spring and autumn equinoxes. This image was taken during the autumnal equinox on September 22, 2013.

Below is an animated gif of the view, going from day to night.

Animation of the Electro-L satellite's view of Earth on September 22, 2013. Credit: Roscosmos / NTSOMZ / SRC "Planeta" / zelenyikot.livejournal.com — Animation of the Electro-L satellite’s view of Earth on September 22, 2013. Credit: Roscosmos / NTSOMZ / SRC “Planeta” / zelenyikot.livejournal.com

Elektro-L orbits Earth in a geostationary orbit 36,000 kilometers above the equator, and with the Sun exactly behind the satellite on the equinox — the day the north and south poles get the same amount of light — the entire disk is fully lit.

You can see the typhoon Usagi raging over Southeast Asia, clouds and rain over Russia and swirling clouds in the ocean near Antarctica.

Electro-L was launched in 2011 and is Russia’s first geostationary weather satellite. It’s a data hog – sending back 2.56 to 16.36 megabits per second, with resolution of 1 kilometer per pixel. You can see the big 5000 x 5000 pixel version at the Electro-L website.

Thanks to Vitaliy Egorov for sharing this image with UT. He has posted the images at his zelenyikot/livejournal website.

September 23, 2013March 16, 2017 by Fraser Cain

Why Are There Seasons?

We’re in the middle of Summer here on Vancouver Island, the Sun is out, the air is warm, and the river is great for swimming.

Three months from now, it’s going to be raining and miserable.

Six months from now, it’s still going to be raining, and maybe even snowing.

No matter where you live on Earth, you experience seasons, as we pass from Spring to Summer to Fall to Winter, and then back to Spring again.

Why do we have variations in temperature at all? What causes the seasons?

If you ask people this question, they’ll often answer that it’s because the Earth is closer to the Sun in the summer, and further in the winter.

But this isn’t why we have seasons. In fact, during Winter in the Northern Hemisphere, the Earth is actually at the closest point to the Sun in its orbit, and then farthest during the Summer. It’s the opposite situation for the Southern hemisphere, and explains why their seasons are more severe.

So if it’s not the distance from the Sun, why do we experience seasons?

We have seasons because the Earth’s axis is tilted.

Consider any globe you’ve ever used, and you’ll see that instead of being straight up and down, the Earth is at a tilt of 23.5-degrees.

The Earth’s North Pole is actually pointed towards Polaris, the North Star, and the south pole towards the constellation of Octans. At any point during its orbit, the Earth is always pointed the same direction.

For six months of the year, the Northern hemisphere is tilted towards the Sun, while the Southern hemisphere is tilted away. For the next six months, the situation is reversed.

Whichever hemisphere is tilted towards the Sun experiences more energy, and warms up, while the hemisphere tilted away receives less energy and cools down.

Consider the amount of solar radiation falling on part of the Earth.

When the Sun is directly overhead, each square meter of Earth receives about 1000 watts of energy.

But when the Sun is at a severe angle, like from the Arctic circle, that same 1000 watts of energy is spread out over a much larger area.

This tilt also explains why the days are longer in the Summer, and then shorter in the Winter.

The longest day of Summer, when the Northern Hemisphere is tilted towards the Sun is known as the Summer Solstice.

And then when it’s tilted away from the Sun, that’s the Winter Solstice.

When both hemispheres receive equal amounts of energy, it’s called the Equinox. We have a Spring Equinox, and then an Autumn Equinox, when our days and night are equal in length.

So how does distance from the Sun affect us?

The distance between the Earth and has an effect on the intensity of the seasons.

The Southern Hemisphere’s Summer happens when the Earth is closest to the Sun, and their winter when the Earth is furthest. This makes their seasons even more severe.

You might be interested to know that the orientation of the Earth axis is actually changing.

Over the course of a 26,000 year cycle, the Earth’s axis traces out a great circle in the sky. This is known as the precession of the equinoxes.

At the halfway point, 13,000 years, the seasons are reversed for the two hemispheres, and then they return to original starting point 13,000 years later.

You might not notice it, but the time of the Summer Solstice comes earlier by about 20 minutes every year; a full day every 70 years or so.

I hope this helps you understand why the Earth – and any planet with a tilted axis – experiences seasons.

September 10, 2013December 23, 2015 by Jason Major

“Oddball” Asteroid is Really a Comet

Spitzer image of an asteroid's surprise coma and tail (NASA/JPL-Caltech/DLR/NAU)

It’s a case of mistaken identity: a near-Earth asteroid with a peculiar orbit turns out not to be an asteroid at all, but a comet… and not some Sun-dried burnt-out briquette either but an actual active comet containing rock and dust as well as CO2 and water ice. The discovery not only realizes the true nature of one particular NEO but could also shed new light on the origins of water here on Earth.

JPL Near-Earth Object database map of 3552 Don Quixote's orbit — JPL Near-Earth Object database map of 3552 Don Quixote’s orbit

Designated 3552 Don Quixote, the 19-km-wide object is the third largest near-Earth object — mostly rocky asteroids that orbit the Sun in the vicinity of Earth.

According to the IAU, an asteroid is coined a near-Earth object (NEO) when its trajectory brings it within 1.3 AU from the Sun and within 0.3 AU of Earth’s orbit.

About 5 percent of near-Earth asteroids are thought to actually be dead comets. Today an international team including Joshua Emery, assistant professor of earth and planetary sciences at the University of Tennessee, have announced that Don Quixote is neither.

an asteroid is coined a Near Earth Asteroid (NEA) when its trajectory brings it within 1.3 AU from the Sun and hence within 0.3 AU of the Earth's orbit. — *An asteroid is coined a near-Earth object (NEO) when its trajectory brings it within 1.3 AU from the Sun and within 0.3 AU of Earth’s orbit. (IAU)*

“Don Quixote has always been recognized as an oddball,” said Emery. “Its orbit brings it close to Earth, but also takes it way out past Jupiter. Such a vast orbit is similar to a comet’s, not an asteroid’s, which tend to be more circular — so people thought it was one that had shed all its ice deposits.”

Using the NASA/JPL Spitzer Space Telescope, the team — led by Michael Mommert of Northern Arizona University — reexamined images of Don Quixote from 2009 when it was at perihelion and found it had a coma and a faint tail.

Emery also reexamined images from 2004, when Quixote was at its farthest distance from the Sun, and determined that the surface is composed of silicate dust, which is similar to comet dust. He also determined that Don Quixote did not have a coma or tail at this distance, which is common for comets because they need the sun’s radiation to form the coma and the sun’s charged particles to form the tail.

The researchers also confirmed Don Quixote’s size and the low, comet-like reflectivity of its surface.

“The power of the Spitzer telescope allowed us to spot the coma and tail, which was not possible using optical telescopes on the ground,” said Emery. “We now think this body contains a lot of ice, including carbon dioxide and/or carbon monoxide ice, rather than just being rocky.”

This discovery implies that carbon dioxide and water ice might be present within other near-Earth asteroids and may also have implications for the origins of water on Earth, as comets are thought to be the source of at least some of it.

The amount of water on Don Quixote is estimated to be about 100 billion tons — roughly the same amount in Lake Tahoe.

“Our observations clearly show the presence of a coma and a tail which we identify as molecular line emission from CO2 and thermal emission from dust. Our discovery indicates that more NEOs may harbor volatiles than previously expected.”

– Mommert et al., “Cometary Activity in Near–Earth Asteroid (3552) Don Quixote “

The findings were presented Sept. 10 at the European Planetary Science Congress 2013 in London.

Source: University of Tennessee press release

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3552 Quixote isn’t the only asteroid found to exhibit comet-like behavior either — check out Elizabeth Howell’s recent article, “Asteroid vs. Comet: What the Heck is 3200 Phaethon?” for a look at another NEA with cometary aspirations.

August 23, 2013December 23, 2015 by Jason Major

An Illustrative Explanation Of Our Solar System

The Solar System: Our Home in Space (screenshot) © Philipp Dettmer Information Design

The Solar System: it’s our home in space, the neighborhood that we all grew up in and where — unless we figure out a way to get somewhere else — all of our kids and grandkids and great-great-great-great-times-infinity-great-grandkids will grow up too. That is, of course, until the Sun swells up and roasts Earth and all the other inner planets to a dry crunchy crisp before going into a multi-billion year retirement as a white dwarf.

But until then it’s a pretty nice place to call home, if I may say so myself.

Edu-film designer Philipp Dettmer and his team have put together a wonderful little animation explaining the basic structure of the Solar System using bright, colorful graphics and simple shapes to illustrate the key points of our cosmic neighborhood. It won’t teach you everything you’ll ever need to know about the planets and it’s not advisable to use it as a navigation guide, but it is fun to watch and well-constructed, with nice animation by Stephan Rether and narration by Steve Taylor.

Check out the full video below:

“Through information design, concepts can be made easy and accessible when presented in a short, understandable edu-film or perhaps an infographic. Whether explaining the vastness of the universe or the tiniest building blocks of life – all information can be presented in a way that everyone understands. Regardless of prior knowledge.”
– Philipp Dettmer

(And come on, admit it… you learned something new from this!)

Credit: Philipp Dettmer Information Design. HT to Colin Lecher at Salon.