The sun is blank today for the 10th straight day and it has been without sunspots this year more than half the time as the current solar cycle heads towards the next solar minimum. Solar cycle 24 is currently on pace to be the weakest sunspot cycle with the fewest sunspots since cycle 14 peaked in February 1906. Solar cycle 24 continues a recent trend of weakening solar cycles which began with solar cycle 21 that peaked around 1980. The last time the sun was this blank in a given year on a percentage basis was 2009 during the last solar minimum when 71% of the time was spotless. That last solar minimum actually reached a nadir in 2008 when an astounding 73% of the year featured a spotless sun - the most spotless days in a given year since 1913.
All indications are that the upcoming solar minimum which is expected to begin in 2019 may be even quieter than the last one which was the deepest in nearly a century. One of the natural impacts of decreasing solar activity is the weakening of the ambient solar wind and its magnetic field which, in turn, allows more and more cosmic rays to penetrate the solar system. The intensification of cosmic rays can have important consequences on such things as Earth’s cloud cover and climate, the safety of our astronauts exploring in space, and lightning.
Read More
There will be a “partial” lunar eclipse next week in the eastern US (“total” eclipse in the rest of the country) and it coincide with a blue moon and supermoon in an event that hasn’t happened in over 150 years. These three lunar events are not uncommon, but it is rare for them to occur at the same time. The eclipse will take place early in the morning on Wednesday, January 31 and it will be somewhat of a challenge for viewers in the eastern US as the moon will be about to set in the western sky and the sky will be getting lighter in the east.
Read More
Solar cycle 24 has turned out to be historically weak with the lowest number of sunspots since cycle 14 peaked more than a century ago in 1906 and by some measures, it is the third weakest since regular observations began around 1755. This historically weak solar cycle continues a weakening trend in solar irradiance output since solar cycle 21 peaked around 1980 and the sun is fast-approaching the next solar minimum. The last solar minimum lasted from 2008 to 2009 and the sun was as quiet during that time as it has been since 1978. The sun is likely to enter the next solar minimum phase within three years or so. The sun has been spotless for 26% of the time in 2017 (90 days) and the blank look should increase in frequency over the next couple of years leading into the next solar minimum.
Read More
Weather satellite data is critical to the accuracy of computer forecast models used by forecasters and the JPSS-1 polar orbiter – now set to launch on Wednesday at 4:47 AM (ET) - will be extremely valuable in that regard. The launch of NOAA’s next-generation polar-orbiting weather satellite was set for today at Vandenberg AFB, but was scrubbed due to a late launch vehicle alarm. The satellite is sitting atop the Delta II rocket that will take it into space early on Wednesday.
Read More
The sun is blank again today and this marks the 70th day of the year in which there have been no visible sunspots which makes up nearly a quarter of the time in 2017. Historically weak solar cycle 24 continues to transition away from its solar maximum phase and towards the next solar minimum. The last solar minimum was historically long and deep lasting from 2008 to 2010. The blank look to the sun will increase in frequency over the next couple of years leading up to the next solar minimum - probably to be reached in late 2019 or 2020. By one measure, the current solar cycle is the third weakest since record keeping began in 1755 and it continues a weakening trend since solar cycle 21 peaked in 1980. One of the impacts of low solar activity is the increase of cosmic rays that can penetrate into the Earth’s upper atmosphere and this, in turn, can impact clouds on Earth. In addition, there is reason to believe that low solar activity can play an important role in winter weather conditions in the central and eastern US as it is well-correlated with more frequent "high-latitude blocking" events.
Read More
The seventh planet from the sun, Uranus, will actually reach its closest point of the year tonight in its orbit to Earth as it “reaches opposition” (i.e., directly opposite the sun). As a result, the icy planet will be visible as a blue-green dot tonight through binoculars and perhaps even with the naked eye if you’re in a dark location.
Read More
The sun has been relatively quiet in recent years and the current solar cycle (#24) is actually on pace to be the weakest in over one hundred years. Even weak solar cycles, however, can produce significant solar storms. In fact, it was this time of year back in 1859 when a super solar storm - now known as the Carrington Event - took place during another weak solar cycle (#10). The event has been named for the British astronomer, Richard Carrington, as he observed from his own private observatory the largest solar flare during this event which caused a major coronal mass ejection (CME) to travel directly toward Earth. Fortunately, solar storms of this magnitude are quite rare as it would very likely have a much more damaging impact on today’s world than it did in the 19th century.
Read More
On August 21st, the US will experience its first “coast-to-coast” total solar eclipse since 1918. On that day, the moon will pass between the sun and Earth and the result will be a 67-mile wide shadow that will cross the country from Oregon to South Carolina. In the DC, Philly and New York City metro regions, this eclipse will be partial with anywhere from about 81% of the sun being covered by the moon in DC to about 72% in New York City. In the "totality zone" where the sun will become covered in its entirety(and of course depending on the local cloud conditions), the sky gets deep twilight blue, temperatures drop noticeably, the winds should die down, bright stars and planets come out, animals and birds may behave strangely like it’s the end of the day, and it can become strangely silent. A total solar eclipse provides a great opportunity for scientists to learn more about the sun's atmosphere as well as our own.
Read More
The “Great American” solar eclipse that is coming on August 21st is not the only space event of interest during the month of August. The annual Perseid meteor shower has actually already begun and it will peak on Saturday, August 12th. The Perseid meteor shower comes every August as the Earth passes through a cloud of dust that comes from Comet Swift-Tuttle as it approaches the sun.
Read More
The total solar eclipse that takes place on August 21st across parts of the US will provide an opportunity for solar scientists to learn more about the sun’s atmosphere including its outermost layer called the corona. In addition, if there is activity on the sun during the upcoming total solar eclipse such as solar prominences or coronal mass ejections, this will provide an opportunity for first-hand observations by solar scientists. Atmospheric scientists and meteorologists will take this opportunity to closely monitor local weather conditions in the totality zone including such parameters as air temperature and surface winds – both of which typically drop off noticeably during the short totality time period. In addition, during a total solar eclipse, the Earth’s upper atmospheric region known as the ionosphere behaves as if it is nighttime and this event will provide an opportunity for atmospheric scientists and meteorologists (and radio enthusiasts) to learn more about the ionization which is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons.
Read More
