Category Archives: Astronomy

Astronomical winter begins with the winter solstice on Monday

The Earth at the Winter Solstice.  The Northern Hemisphere sees their shortest day of the year while the Southern Hemisphere gets its longest. (NASA)
The Earth at the Winter Solstice. The Northern Hemisphere sees their shortest day of the year while the Southern Hemisphere gets its longest. (NASA)

Astronomical winter arrives in Thornton tonight and with the solstice also comes the shortest day of the year.

Winter officially begins at 9:49pm today. The Winter Solstice occurs when the North Pole is tilted at its furthest from the sun – 23.5 degrees away. This results in the shortest day of the year in the Northern Hemisphere.

Here in Denver, with sunrise at 7:17am and sunset at 4:39pm, our day today is 9 hours, 21 minutes and 14 seconds long. Tomorrow it will be one second longer and each day from now through to the Summer Solstice in June will get gradually longer as well.

While we have a short day today, it is nothing like what will be experienced in the Arctic Circle.  Areas north of there to the North Pole will have no direct sunlight at all.  Conversely, areas south of the Antarctic Circle toward the South Pole will have 24 hours of daylight and have a midnight sun.

Did you know that there is a difference between the astronomical seasons that we are discussing here and meteorological seasons?

Meteorological seasons differ slightly and are geared toward matching the calendar with the annual temperature cycle. This is done primarily for meteorological observing and forecasting and in many ways it is more logical than the astronomical seasons.

For the Northern Hemisphere, the meteorological spring covers the months of March, April and May. Summer brings the hottest months of the year and so meteorological summer is June, July and August. Meteorological fall then is September, October and November followed by the coldest months of December, January and February as meteorological winter.

NASA Outlines Plan For Humanity’s Journey To Mars

Mars, despite its inhospitable climate and heavily irradiated surface that would kill humans in a matter of minutes, has been a source of unending fascination for scientists and science fiction writers alike. In recent years, this fascination has translated into concrete plans for a manned mission to the red planet, with the goal of eventually establishing… Continue reading NASA Outlines Plan For Humanity’s Journey To Mars

Supermoon eclipse provides rare celestial event Sunday

Path of the moon during the total lunar eclipse on September 27, 2015. (Fred Espenak)
Path of the moon during the total lunar eclipse on September 27, 2015. Click for a larger view. (Fred Espenak)

A total lunar eclipse coupled with a ‘supermoon’ will bring a very unusual scene to the sky on Sunday.  Taken separately, the two events are not quite as extraordinary or rare.  However, this will be the first time in 33 years they have occurred at the same time and the last for another 18 years.

The moon’s orbit around Earth is not a perfect circle and when it is at its closest to us, it appears quite a bit larger to our eye – hence the name ‘supermoon.’

On Sunday it will be about 31,000 miles closer to Earth than it is at its farthest point. According to NASA, this results in it appearing to be about 14% larger and 30% brighter.

The total lunar eclipse will be our second of 2015 and fourth in the past two – a tetrad of eclipses.  During these, the moon finds itself in the Earth’s shadow and without direct sunlight hitting its surface, the moon turns an eerie orange / red color – a ‘blood moon.’

The last time these two events coincided was in 1982 and the next time won’t be until 2033.  As NASA scientist Noah Petro said, “That’s rare because it’s something an entire generation may not have seen.”

When and where to watch?

The partial eclipse begins at 7:07pm MDT on Sunday, September 27, 2015 with totality starting at 8:11pm.  The moon will then be completely eclipsed for a little more than an hour with mid-eclipse at 8:47am.  The waning partial eclipse will end at 10:27pm.

One catch for viewing the entire event here along the Front Range is that when it begins, the moon will actually be just starting to rise on the eastern horizon.  However, at mid-eclipse the moon will be 21 degrees above the horizon to the east southeast providing a nice view not far above the landscape.

Anyone in the area with a clear view of the lower, eastern sky should have no problem viewing the event.

Will Mother Nature cooperate?

Our unseasonably warm temperatures will be continuing through the weekend so there are no concerns about it being too cold to go outside.  Clouds, however, are something to watch closely for.  Some atmospheric moisture is expected late in the day Sunday and it is possible cloud cover may impact the clear viewing.

On the day of the eclipse, check our hour-by-hour outlook for the latest sky cover forecast.

What is the ‘blood moon’ and tetrad?

April 15, 2014 - The lunar eclipse is seen half-way to totality, the total lunar eclipse, and half-way between totality and the end. (Tony's Takes)
April 15, 2014 – The lunar eclipse is seen half-way to totality, the total lunar eclipse, and half-way between totality and the end. Click for a larger view. (Tony’s Takes)

During totality, the moon will be rendered orange / red as the Earth’s shadow envelops the moon.  Many are calling this a ‘blood moon’ but the meaning behind that term isn’t exactly clear.

As written on EarthSky.org, some attribute it to the lunar tetrad – four successive full lunar eclipses without any partial eclipses.  Tomorrow morning’s eclipse is the second in the lunar tetrad with each full lunar eclipse coming six months apart.

The blood moon as it pertains to these eclipses should not be confused with the October full moon which is also referred to as a blood moon in folklore.

Shedding light on the rare Sept. 27 supermoon eclipse

Ashley Morrow, NASA Goddard Space Flight Center Coming soon for the first time in more than 30 years: you’ll be able to witness a supermoon in combination with a lunar eclipse. Late on Sept. 27, 2015, in the U.S. and much of the world, a total lunar eclipse will mask the moon’s larger-than-life face for more… Continue reading Shedding light on the rare Sept. 27 supermoon eclipse

Winter Solstice brings shortest day of the year, change of seasons

The Earth at the Winter Solstice. (NASA)
The Earth at the Winter Solstice. (NASA)

Astronomical winter arrives in Thornton today and with the solstice also comes the shortest day of the year.

Winter officially begins at 4:03pm today.  The Winter Solstice occurs when the North Pole is tilted at its furthest from the sun – 23.5 degrees away.  This results in the shortest day of the year in the Northern Hemisphere.

Here in Denver, with sunrise at 7:18am and sunset at 4:39pm, our day today is 9 hours, 21 minutes and 13 seconds long.  Tomorrow it will be one second longer and each day from now through to the Summer Solstice in June will get gradually longer as well.

Did you know that there is a difference between the astronomical seasons that we are discussing here and meteorological seasons?

Meteorological seasons differ slightly and are geared toward matching the calendar with the annual temperature cycle.  This is done primarily for meteorological observing and forecasting and in many ways it is more logical than the astronomical seasons.

For the Northern Hemisphere, the meteorological spring covers the months of March, April and May.  Summer brings the hottest months of the year and so meteorological summer is June, July and August.  Meteorological fall then is September, October and November followed by the coldest months of December, January and February as meteorological winter.

Lunar eclipse to bring ‘blood moon’ for second time of year

Diagram of the October 8, 2014 total lunar eclipse.  (Image courtesy Fred Espenak / EclipseWise.com)
Diagram of the October 8, 2014 total lunar eclipse. Click for a larger view. (Image courtesy Fred Espenak / EclipseWise.com)

For the second time of the year, sky gazers will have the opportunity to witness a total lunar eclipse.  This is in fact the second in a series of four consecutive total lunar eclipses, an event called the lunar tetrad.

Colorado and the rest of the western United States will have a front row seat to the celestial event occurring on the morning of Wednesday, October 8.

When and where to watch? 

The partial eclipse begins at 3:15am MDT with totality starting at 4:25am.  The moon will then be completely eclipsed for approximately one hour with mid-eclipse at 4:55am.  The waning partial eclipse will end at 6:34am.

Anyone in the area with a clear view of the western sky should have no problem viewing the event.

When the event begins the moon will be about 40 degrees above the horizon.  It will be sinking closer to the horizon as the eclipse progresses.  At mid-eclipse, the moon will be 25 degrees above the horizon.  When the moon emerges from the shadow of the Earth, it will barely be visible to the west as it sets.

Will Mother Nature cooperate?

Current models do indicate there will be some overnight cloudiness lasting into tomorrow morning as we see an increase in atmospheric moisture. Grids indicate 40% sky cover for the time period near mid-eclipse.  The timing and location of those clouds may limit viewing a bit.  The good thing is that we are expecting a mild night with temperatures right around 50 degrees in Thornton during the event.  Click here to view the hour-by-hour point forecast for the latest.

What is the ‘blood moon’ and tetrad?

April 15, 2014 - The lunar eclipse is seen half-way to totality, the total lunar eclipse, and half-way between totality and the end. (Tony's Takes)
April 15, 2014 – The lunar eclipse is seen half-way to totality, the total lunar eclipse, and half-way between totality and the end. Click for a larger view. (Tony’s Takes)

During totality, the moon will be rendered orange / red as the Earth’s shadow envelops the moon.  Many are calling this a ‘blood moon’ but the meaning behind that term isn’t exactly clear.

As written on EarthSky.org, some attribute it to the lunar tetrad – four successive full lunar eclipses without any partial eclipses.  Tomorrow morning’s eclipse is the second in the lunar tetrad with each full lunar eclipse coming six months apart.

The blood moon as it pertains to these eclipses should not be confused with the October full moon which is also referred to as a blood moon in folklore.

For more information:

Total lunar eclipse to bring ‘blood moon’ on Tax Day

Diagram of the April 14 / 15, 2014 total lunar eclipse. Click for a larger view. ( Fred Espenak, http://www.MrEclipse.com)
Diagram of the April 14 / 15, 2014 total lunar eclipse. Click for a larger view. ( Fred Espenak, http://www.MrEclipse.com)

For those willing to forgo a bit of sleep tonight, a gaze skyward will provide a look at the first lunar eclipse of 2014.

The entire celestial event will be visible from Colorado beginning at 11:58 pm tonight as the partial eclipse begins.  Totality occurs at 1:07 am MDT on the morning of April 15 and lasting until 2:25 am.  The event will be over at 3:33 am.

Current weather forecasts for Thornton and the Denver metro area show that we should have mostly clear skies tonight allowing prime viewing of the event.  It will however be quite cold with temperatures in the mid to upper 20s.  Check our 48 hour point forecast for what to expect.

During totality, the moon will be rendered orange / red as the Earth’s shadow envelops the moon.  Many are calling this a ‘blood moon’ but the meaning behind that term isn’t exactly clear.

As written on EarthSky.org, some attribute it to the lunar tetrad – four successive full lunar eclipses without any partial eclipses.  Tonight’s eclipse begins the lunar tetrad with each full lunar eclipse coming six months apart.

The blood moon as it pertains to these eclipses should not be confused with the October full moon which is also referred to as a blood moon in folklore.

Also note that Mars is at its closest point to Earth in 6 years.  The red planet will be visible at about the 2:00 position in relation to the fully eclipsed moon.

For more information:

NASA releases video recreating iconic Apollo 8 Earthrise image

Planet Earth is seen by humans in lunar orbit for the first time during Apollo 8.
Earth is seen by humans in lunar orbit for the first time during Apollo 8. (NASA)

It was Christmas Eve in 1968 when three brave astronauts, the first humans to leave Earth orbit, circled the moon. As the 45th anniversary of that event approaches, NASA has released a video that recreates the iconic Earthrise image that has captivated the world since.

Using imagery obtained from its Lunar Reconnaissance Orbiter, the video released by NASA yesterday allows viewers to see Earthrise as it was first witnessed 45 years ago.

Audio from the Apollo 8 mission provides commentary from the astronauts as they conducted routine observations – until the spacecraft oriented itself to allow them view the planet. The astronauts then scramble to get cameras in place to capture the event.

Read the rest of this story and check out the amazing video on Examiner.com

NOAA imagery shows population centers and road transportation network

The Suomi NPP satellite acquired two nighttime images early on October 1, 2013, for this natural-light, mosaic view (top) of the continental United States. (NOAA)
The Suomi NPP satellite acquired two nighttime images early on October 1, 2013, for this natural-light, mosaic view (top) of the continental United States. (NOAA)

Millions of Americans will be taking to the highways of byways of the nation in the coming weeks for various holiday travels.  Imagery released by NOAA this week shows how the nation’s major roadways intersect with the major population centers.

A nighttime satellite image of the nation was taken by the Suomi NPP satellite taken last month near the new moon when light from space was relatively low.  This allowed NOAA to generate an image showing population centers from coast to coast.

When overlaid with a graphic of major interstate highways, railroads, and rivers, the images provide insight into how the nation evolved.

Early in the nation’s history, rivers were the major means of transportation and population centers developed around them.  As we expanded and the national highway system took shape, major roads connected the cities.

Below we have added an interactive slider to allow you to compare the surface travel networks with the satellite image.  Simply move it side to side to compare.

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