Mercury is best seen from 3.35 am before Sunrise in the constellation of Taurus. Venus is best seen from 9.35 pm to 11.40 pm in the constellation of Cancer, after in the constellation of Leo. Mars is still too close to the Sun, an elongation or distance to the Sun only 4.3° in the Western morning. Jupiter is best seen from 10 pm to 11.50 pm in the constellation of Leo. Saturn is best seen from 10.30 pm to 3.10 am in the constellation of Libra.
The Moon is a First Quarter Moon on Wednesday 24 June, and is a Full Moon on Wednesday 01 July. The Sun rises at 4.41 am, and sets at 9.37 pm.
Wednesday 24 June
Today in 1963, the first demonstration of a home video recorder was made at the BBC News Studios in London.
At 12.02 pm, at noon, it is First Quarter Moon. This is the smallest First Quarter Moon of the year. Former smaller First Quarter Moon was on 07 May 2014. The next smaller First Quarter Moon is on 10 August 2016
At 6.10 pm, not that you will notice (as the planet is visible in the early mornings), Mercury is in Greatest Elongation. Mercury is 22.5° West in the mornings.
Look for the Earthshine on the Moon at 10.30 pm. After midnight, at 0.51 am, a very bright Iridium flare is visible in the South West at an altitude 56° in the constellation of Hercules. Look for Mercury, rises about an hour before Sunrise at 3.43 am in the East North East, in the constellation Taurus. Another bright flare at 4.04 am in the East at an altitude of 39° in the constellation of Pisces.
Thursday 25 June
You will need a special Solar telescope to see, but the International Space Station (ISS) will transit the Sun at 4.14 pm in the afternoon (in daylight!). The transit will be visible between Newhaven and Pikehall. Contact me if you need updated calculations the day before.
At 9.37 pm, for the Ashbourne area, we have the latest Sunset of the Year. At bit after, at 9.45 pm a flare might be seen in twilight in the North North East at an altitude of 72° in the constellation of Ursa Minor. And another flare at 11.18 pm in the West at an altitude of 36° in the constellation of Coma Berenices.
At midnight the Moon is close to the star The Virgo. The Limb separation is 2.02° or 4.06 lunar diameters. Mercury rises at 3.40 am in the North East in the constellation Taurus. Less than an hour before Sun rise, a flare appears at 3.58 am in the East at an altitude of 39° in the constellation of Pisces.
Friday 26 June
Today it is Charles Messier's 285th Birthday (born in 1730). Messier was a French astronomer who discovered 15 comets. He was the first to compile a catalog of "M objects." The Messier Catalogue contained 103 star clusters, nebulae, and galaxies.
At 11 pm, the Great Red Spot transits the planet Jupiter. The altitude is only 7°, but look later when Jupiter is higher in the sky and the Great Red Spot moved along the Jupiter disc. You will need a small telescope or binoculars to see. At 11.12 pm a flare appears in the West at an altitude of 36° in the constellation of Coma Berenices.
At 3.39 am on Saturday morning, Mercury rises in the North East in the constellation of Taurus. Can you locate?
Saturday 27 June
At 3.37 am on Sunday morning Mercury rises in the North East in the constellation of Taurus.
Sunday 28 June
At 7 pm, not that you will see in the evening, Mercury’s magnitude brightens to 0 mag. Look in the early mornings for Mercury.
The Moon close to the star Zuben Elakrab just after 11 pm in the constellation Libra. The limb separation is 2.05° or 3.98 lunar diameters. A very bright Iridium flare appears at 11.09 pm in the West at an altitude of 33° in the constellation Leo.
At 2 am Monday morning the Moon is close to Saturn. The limb separation is only 1° or 1.95 lunar diameters. Be aware, the Moon is low on the horizon. A little after 2 am, the Moon is close to the star The Lib. The limb separation is 1.32° or 2.56 lunar diameters. Mercury rises at 3.16 am in the North East in the constellation of Taurus. At about an hour before Sun rise a bright flare appears at 3.49 am in the East South East at an altitude of 43° in the constellation of Andromeda.
Monday 29 June
Before Moon rise (you will not be able to see) at 5.06 pm, the Moon has its maximum Libration West. The crater Grimaldi is tipped into the Earth's view.
At 11.50 pm the Moon is close to a multiple star system. Close to Chi Oph with limb separation of 2.28° or 4.37 lunar diameters. And close to Phi Oph with limb separation of 2.12° or 4.06 lunar diameters.
After midnight, at 0.30 am a flare appears in the South West at an altitude of 52° in the constellation of Serpens Caput. Another flare appears at 2.07 am in the South South East at an altitude of 59° in the constellation of Vulpecula. Mercury rises at 3.35 am in the North East in the constellation of Taurus. About an hour before Sun rise, at 3.42 am, a flare appears in the East South East at an altitude of 43° in the constellation of Andromeda.
Not that you will notice in full daylight, but at 5.50 am, Mercury is in Dichotomy or Half phase. The inner planets Venus and Mercury appears in phases like our Moon. You will need a telescope to see the phases.
Tuesday 30 June
Leap second today – see Special on these pages.
In 1973, a solar eclipse, predicted as the longest for 1000 years, was observed by British, French and American scientists aboard the French prototype Concorde 001 supersonic aircraft on a flight from Las Palmas in the Canaries to Fort Lamy in Chad. The path of totality crossed the Atlantic, the Sahara Desert and East Africa. The moon’s shadow travelled at over 3000 km per hour. Flying at 55000 feet, the jet’s speed made possible a continuous view of the solar eclipse for 74 minutes, ten times longer than could be seen by an observer on the ground.
At 7.24 pm, about 20 minutes before Moon rise, the Moon is in maximum Libration.
Mercury rises on Wednesday morning at 3.35 am in the North East in the constellation of Taurus. At 4.49 am, at Sunrise, and you will not see, Venus close to Jupiter. Only 20.1' separated from center of Jupiter (less than a Moon diameter!). Watch this in the evening of Wednesday.
Wednesday 01 July
At 7.49 am The Moon in maximum declination South. This is the 2nd southernmost Moon position of the year. Former more southern Moon position was at 18 January 2015. Next more southern Moon position is at 24 May 2016.
At 8.51 am Venus in conjunction with Jupiter. Only 20.7' separated from center of Jupiter. And at 3.15 pm Venus in conjunction in Right Ascension with Jupiter. Venus is only 24.0' separated from center of Jupiter. Watch these two planets at and after Sunset. A beautiful evening show and worthwhile a picture.
At 7.04 pm the Moon in maximum Libration South. The South Pole of the Moon is tipped into the Earth's view. The Moon rises at 8.39 pm.
A flare appears at 10.59 pm in the West at an altitude of 29° in the constellation of Leo. Only 2 minutes later, at 11.01 pm a brighter flare is visible at nearly the same spot in the West at an altitude of 28° in the constellation Leo.
At 3.19 am it is Full Moon. This is the southernmost Full Moon of the year. The former more southern Full Moon was at 13 June 2014. The next more southern Full Moon is at 20 June 2016.
Enjoy your extra time on 30th June
Anything planned for Tuesday 30 June? If so, you will have an extra second, to celebrate, to sleep, to work, …. The official Coordinated Universal Time (UTC) will read 23:59:60 rather than resetting to 00:00:00. For Ashbourne, it will be an hour later as UTC. This extra second, or “leap second,” is needed to resynchronize our land-based clocks with the Earth’s rotation. Each year our planet is slowing down very slightly. Nothing to worry about of course. This is the 26th time we’ve added a second to the day since the practice began in 1972. The last leap second we had was in 2012, therefore 2008, 2005, 1998, etc.
Due to tidal forces between the Earth and Moon, our planet’s rotation is slowing down, adding 1.4 milliseconds to our days every century. I am sure you probably didn’t notice. But the 1.4 milliseconds adds up over time. During the time of the dinosaurs, the typical day on Earth was just 23 hours. In fact, the last true 24 hour rotation, exactly 86 400 seconds, occurred in 1820. Since then, the day has lengthened by 2.5 milliseconds. We have these precise measurements thanks to punctual scientists who have been monitoring Earth’s rotation using a technique called Very Long Baseline Interferometry (VLBI).
The last leap second gave some issues in 2012 on some popular websites with clocks synced to standard civil time. Websites like LinkedIn reported problems with the change. When the clock strikes midnight, the 59th second is repeated twice, or a 60th second appears, in order to sync time. This puts some computers into a panic because they register this as an error and their CPUs can overload. To avoid this Google added a millisecond of time to their servers with each update so they were caught up with the new time when the leap second occurred.
But how do we “measure” time? For Newton time was absolute, for Einstein it was relative … An atom gives a precise time. A second is defined by exactly 9 192 631 770 oscillations of a cesium atom. UTC or Coordinated Universal Time, is the time standard used to determine local times in time zones worldwide. It is primarily based on the combined output of several highly precise atomic clocks, a statistical time scale called International Atomic Time (TAI). A normal day has 86 400 seconds, but in the atomic time scale 1 second is not defined as one 86 400th of the time it takes Earth to rotate around its axis but as the time it takes a Cesium-133 atom at the ground state to oscillate precisely 9 192 631 770 times. Universal Time (UT1), also known as astronomical time or solar time, refers to the Earth's rotation. It is used to compare the pace provided by TAI with the actual length of a day on Earth.
Leap seconds can be positive where one second will be added; or negative where one second will be omitted. Well, at least in theory. So far, all leap seconds were positive, and given the slowing of the Earth's rotation it is unlikely that a negative leap second will ever occur.
The speed of the Earth's rotation differs from day to day and from year to year, so the difference between Universal Time and the International Atomic Time varies accordingly. The difference over one year was 0.28 seconds in 2011 for example and only 0.02 seconds in 2001.
Not only do days become longer, but the rate at which day lengths increase also grows over time. Only by about two thousandths of a second per century though. This means that at the moment days are 0.002 seconds longer than the sum of 86,400 seconds measured by atomic clocks. In 100 years they are expected to be 0.004 seconds “too long”.
A normal year has 365 days but a Leap year has 366. The Earth takes a little longer than 365 days to go around the Sun so we add an extra day in February every four years to keep the calendars and the seasons aligned.
A leap year, also called intercalary or bissextile year, is a year with one additional day. This is to keep the calendar year synchronized with the astronomical or seasonal year. Because seasons and astronomical events do not repeat in a whole number of days, calendars that have the same number of days in each year, over time, drift with respect to the event that the year is supposed to track. By inserting, what they call or intercalating, an additional day into the year, the drift can be corrected. A year that is not a leap year is called a common yea.
A Leap Day, 29 February, is added to the calendar in Leap Years. This extra (intercalary) day makes the year 366 days long. It does not have 365 days, like a common (normal) year. Leap Years occur nearly every 4 years in our modern Gregorian Calendar. Next year 2016 is a Leap Year, so the next Leap Day falls on Monday 29 February 2016. The last Leap Day was on Wednesday 29 February 2012. In the case of lunisolar calendars, a month will be added. The Chinese calendar is lunisolar, so a leap year has an extra month, often called an embolismic month after the Greek word for it.
A person born on 29 February may be called a "leapling" or a "leaper". In common years, they usually celebrate their birthdays on 28 February. In some situations, 1rst March is used as the birthday in a non-leap year, since it is the day following 28 February.
And more about time …
The Moon was used as a form of calendar more than 6000 years ago.
A sundial uses the position of the Sun to measure time.
Pendulums do accurately measure time and was discovered by Galileo Galilei about 400 years ago.
Time began with the formation of the universe in the instant of the Big Bang 13.7 billion years ago
Between 1929 and 1940 the Soviet Union changed the length of the week three times. In 1930 Stalin abolished weekends to fulfil work quotas. In 1931 it went to a six-day week and back to a seven-day week in 1940.
In the International Fixed Calendar was invented by Englishman Moses Bruine Cotworth in 1859 There are 13 months, with the extra month called Sol.
In 1836 John Belville began to sell time. He set his pocket watch at the Greenwich Observatory where he worked every morning and would sell the precise time to clients in the City. The family business went on until 1940.
The Julian calendar assumed a year is exactly 365.25 days, and about 10 and three quarter minutes too long. By 1582, it was 10 days out of sync, so Pope Gregory XIII decreed that 10 days should be lost to put things right. So we changed into the Gregorian Calendar; what we have now.
Easter is the first Sunday after the first full moon after the spring equinox
Universal Time (UT) was created at the Washington Meridian Conference in 1884. This is the basis for the 24 hour time zone system we know today. At the time, Greenwich Mean Time (GMT) was chosen as the world’s time standard. The reference line or starting point, the Prime Meridian, was determined to be the transit circle at the Royal Observatory in Greenwich, London. The transit circle is a part of the telescope's mechanics and it is still cited as the Prime Meridian's original reference.
In 1960, the International Radio Consultative Committee formalized the concept of UTC, and it was put into practice the year after. The name Coordinated Universal Time was officially adopted in 1967.
Until 1972, Greenwich Mean Time (also known as Zulu time) was the same as Universal Time (UT). Since then, GMT is no longer a time standard. Today, Greenwich Mean Time is only the name of a time zone that is used by a few countries in Africa and Western Europe, including the UK during winter and all year in Iceland.
The United Kingdom is not on Greenwich Mean Time (GMT) all year. During Daylight Saving Time (DST) the correct time zone is British Summer Time (BST). Daylight Saving Time (DST) is a way of making better use of the natural daylight by setting your clock forward one hour during the summer months, and back again in the fall.
To remember which way to set your watch, keep in mind “spring forward, fall back”. You set your clock forward in the spring when DST starts and lose one hour, and back one hour when DST ends in the fall and regain one hour.
Some studies show that DST could lead to fewer road accidents and injuries by supplying more daylight during the hours more people use the roads. Other studies claim that people's health might suffer due to DST changes.
DST is also used to reduce the amount of energy needed for artificial lighting during the evening hours. However, many studies disagree about DST's energy savings and while some studies show a positive outcome, others do not.
US inventor and politician Benjamin Franklin first proposed the concept of DST in 1784, but modern Daylight Saving Time first saw the light of day, in 1895 when an entomologist from New Zealand, George Vernon Hudson, presented a proposal for a two-hour daylight saving shift. However, Germany was the first country to implement DST on 30 April 1916 when the clocks were set forward at 11 pm or 23:00.
A half adjustment was sometimes used in New Zealand in the first half of the 20th century. Australia's Lord Howe Island (UTC+10:30) follows a DST schedule in which clocks are moved 30 minutes forward to UTC+11, which is Australian Eastern Daylight Time (AEDT) during DST.
Today clocks are almost always set one hour back or ahead, but throughout history there have been several variations, like half adjustment (30 minutes) or double adjustment (two hours), and adjustments of 20 and 40 minutes have also been used. A two-hour adjustment was used in several countries during the 1940s and elsewhere at times.
Facts or myths?
Count the seconds between seeing a flash and hearing thunder. Three seconds' delay means the lightning strike is 0.6 miles away.
Beans, peas and tomatoes are said to grow best if planted in the second week after the new moon.
Hummingbirds beat their wings 90 times a second when they are hovering. Flies can beat theirs more than 1,000 times a second.
When the railways first reached Bristol, trains seemed to leave 11 minutes too early. The problem was the drivers had come from London, 200 miles west, where sunrise is 11 minutes earlier. The only sensible solution, applied in 1940, was for all UK trains to use London time or "railway time".
Legend says the first Roman calendar came from Romulus, who was raised by wolves with twin brother Remus and founded Rome in 735BC. He was keen on the number 10, so his years had only 10 months.
At Julius Caesar's command in 46BC two new months were introduced - July named after him and August after his successor Augustus. This Julian calendar also had leap years.
Leap Day as a concept has existed for more than 2000 years, and is still associated with age-old traditions, folklore and superstition. One of the most popular traditions is that women propose to their boyfriends. In Finland, the tradition is that if a man refuses a woman's proposal on leap day, he should buy her the fabrics for a skirt. In Greece, marriage in a leap year is considered unlucky. One in five engaged couples in Greece will plan to avoid getting married in a leap year.