Earth’s Warming Climate

The year 2018 ranked as the fourth warmest since 1880. The three warmer years were 2016, 2017, and 2015 according to scientists at NASA’s Goddard Institute for Space Studies (GISS).

“2018 is yet again an extremely warm year on top of a long-term global warming trend,” said GISS Director Gavin Schmidt. Since the 1880s, the average global surface temperature has risen about 1°Celsius (2°F). According to Schmidt and colleagues, this warming has been driven in large part by increased emissions of carbon dioxide and other greenhouse gases into the atmosphere through human activities.

Surface temperature measurements of the Earth by NASA come from 6,300 locations. They include weather stations, ships and buoys at sea, and Antarctic research stations. The measurements produce the global average temperatures during the year. The baseline period from 1951 to 1980 is used as the mean value for comparison. The difference between the current readings and the 1951-1980 mean is accurate to within 0.1˚F with a 95% certainty level according to NASA.

This chart plots the monthly annual values from 1880 to 2018. Each time a record warm annual mean is set, it displays the year in the right margin. The most recent decades show rapid increases in the annual mean. It will cycle through the values a few times. Reload to see it again.

NASA Earth Observatory | Joshua Stevens | Goddard Institute for Space Studies

Scientists from multiple agencies agree on the rising temperature trend. The following plot shows annual mean variations from the 1951-1980 mean. Annual variations clearly stand out as wiggles in the plot. The steeper warming trend since 1980 is clear.

Five agencies are plotted together: NASA, NOAA, the Japan Meteorological Agency, the Berkeley Earth research group, and the Met Office Hadley Centre (UK). They all show the same trend and closely match the annual variations of each other.

NASA Earth Observatory | Joshua Stevens | Goddard Institute for Space Studies

I am encouraged when I read that more people believe global warming is taking place. Presently, about 70% of those in the U.S. agree. My post on the Yale public opinion survey is here. Are we going to do anything about it? Individually, we can take measures to reduce the carbon footprint of ourselves and homes. That isn’t enough.

Will our government agencies take on the challenges to guide the country toward better outcomes for the sake of our children and grandchildren? Will our nation join others to mount a global effort? At this time, I don’t see it happening. We should be leading the way with ideas and technologies. Give people direction. Motivate companies to be innovative about reducing the carbon footprint we impose upon this planet. How great would that be to see such a revolution? It could stimulate the economies of the world and give future generations a more livable planet.

Looking back from sometime in the future, will we see ourselves rising to meet the challenges? Or, will we merely see more people recognizing that they are in a worsening situation and doing nothing about it?


Viewing Heavenly Bodies | 2019

🔭  Updates an earlier post to include recent changes and new information.  🔭  

Desktop planetarium software helps plan viewing sessions and keep track of the planets and Moon. Many products are available for all computer platforms and smartphones. A Google search yields links to many sources. Open source and free Stellarium is on my desktop computer. It can be customized to your location and has a nice look and feel. For Android and Mac phones and tablets, I like SkySafari. It isn’t free but is inexpensive.

Online planetarium sites are popular and offer many features. Below are highlights of a few I like. With multiple features, a unique look and feel, and different levels of detail, they can help satisfy your curiosity about astronomical events. I welcome reader questions or reviews about using these tools or others you find helpful.



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An Opportunity To Be Missed

I knew it would happen someday. NASA officially declared the Mars Opportunity Rover mission was over. It was active for nearly 15 years and had driven more than 26 miles exploring craters, various rock features, and the weather. Last year, a global dust storm on Mars darkened the skies for many weeks. Opportunity went into a hibernation to save power. After the dust settled and the sun returned, multiple efforts to make contact failed. This is the final transmitted image back in June 2018.

Previously in 2010, Spirit, the other identical rover, had succumbed to the harsh Martian conditions. Both were launched in 2003. They landed with the aid of airbags to soften the impact. They were ‘warranted’ for 90 day missions. Spirit exceeded that by 20x.

Randall Munroe of xkcd published a nice commemorative cartoon for the occasion. Thanks to the intrepid rover for taking us along during its explorations.

Randall Munroe |

NASA published this short video showing some of the highlights of the Opportunity mission.

Dial-a-Moon | 2019

How will the Moon look on any date in 2019? What will it look like on your birthday? Find out at NASA Dial-a-Moon. Here is Dial-a-Moon for southern hemisphere readers.

8 Feb 2019

Enter any month and day to see a high definition image. The composite images of Dial-a-Moon are made from those of the Lunar Reconnaissance Orbiter (LRO) in low altitude orbit around the Moon since 2009.

You may leave the universal time (UT) at the default value. Your local to Universal time conversion can be done at this link. Or, type ‘universal time’ into Google. Go back to Dial-a-Moon to enter the UT.

A Year of Moon Motions

The collection of accurate images of the Moon for each hour have been made into the movies below each lasting about 5 minutes. Try watching full screen for the best effect. Versions of the movie are available for readers in the northern and the southern hemispheres.

I explain the Moon’s peculiar wobble and tipping motions at this blog post.

Northern hemisphere

Southern hemisphere

Ultima Thule | Best View by New Horizons

The New Horizons spacecraft returned this detailed image of Ultima Thule to Earth on 18-19 Jan 2018. It was captured 7 minutes before the closest approach to Ultima Thule at a distance of 4,200 mi (6,700 km). The signal of digital bits traveled at the speed of light for 6 hrs before reaching the antenna at Earth so we could see it.


The shape of Ultima Thule was discovered in July 2017 when it passed in front of a distant star as seen from Earth. Twenty four telescopes were lined up across Argentina where the shadow of Ultima Thule was to pass as it occulted the distant star. The scopes were coordinated with precise time markers. The best-fit of their timings suggested a bi-lobed object. What an amazing prediction considering UT is only about 20 mi (30 km) across and measured from more than 4 billion miles away.

This is probably the oldest and most primordial object we will ever see in such detail.

Ultima Thule belongs to a class of Kuiper belt objects called the “Cold Classicals,” which have nearly circular orbits with low inclinations to the solar plane, and which have not been perturbed since their formation perhaps 4.6 billion years ago. Ultima Thule will therefore be the most primitive planetary object yet explored, and will reveal to us what conditions were like in this distant part of the solar system as it condensed from the solar nebula.


What’s next for New Horizons? Hopes are high for extensions to the mission into 2019 and beyond. It will take into 2020 to download all the data stored in the memory banks. With remaining fuel, New Horizons might survey the field ahead and redirect slightly to pass by other Kuiper Belt objects. Stay tuned to see what might happen.

Ships Passing in the Night

It was 6:30 pm on 24 Jan 2018. The International Space Station was due to pass directly over our part of Iowa from WSW to NE. It was 3˚F outside with more than a foot of snow on the ground. Instead of going outside, I set the iPad in the bedroom window, closed the door, and recorded the pass for 6 minutes. While I watched the spaceship cruise above the trees at 5 mi/sec, an airship also cruised over at about 0.2 mi/sec. The stars silently observed from their perches. I stayed warm.

NightCap Camera | iPad2 | ISO=1536 | 356 sec | Click to embiggen

Ceres | My First Views

Update: Second date of views (4 Jan 2019) is at the bottom of this post.

The largest asteroid Ceres has been orbited by the ion-engine powered DAWN spacecraft since early 2015. DAWN ran out of fuel to maneuver in October 2018 and will remain silent in orbit at Ceres for decades. Previous to Ceres, it visited the second largest asteroid Vesta. This fly-over video gives a close view of Ceres.

The asteroid is far away and quite small and dim. It is not something most people have ever seen with the naked eye or in a telescope. I’ve been tracking Ceres with desktop planetarium software with hopes to see it. I am happy to report success.

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