There are comets visible from Earth many nights, they are just too faint to be seen easily. So, there is a continuum of brightness -- comets from very faint to quite bright. The brightest are the spectacular ones that get in the news. Also, bright ones may be discovered not long before they are visible. If I remember correctly, McNaught, of January/February 2007, the second brightest comet since 1935, was discovered about 6 months before it came close.
The majority of the comets that we see are long-term comets, comets that have "never" been seen during the course of human history. Or at least, comets that were never recorded in the history books.
So most of the comets are, for all practical purposes, "new"; we are unable to predict their appearance, either because no one wrote it down last time, or because the records did not survive the thousands of years from then till now. Our history books only go back about 3000 years, and beyond that is legend - or is lost completely.
So we are unable to say with any certainly what comets will be visible in the next 20 years. Keep watching the skies, and read spaceweather.com for the up-to-the-minute details.
Many comets are irregular - they may come back after millions of years, or not at all. So, it can't always be known in advance when there will be a comet.
Many comets are irregular - they may come back after millions of years, or not at all. So, it can't always be known in advance when there will be a comet.
Many comets are irregular - they may come back after millions of years, or not at all. So, it can't always be known in advance when there will be a comet.
Many comets are irregular - they may come back after millions of years, or not at all. So, it can't always be known in advance when there will be a comet.
Halley's Comet has an orbital period of about 75.3 years. The next visit (called its perihelion - the closest point to the Sun) is expected in July 2061.
The extremely eccentric orbit of Halley's Comet brings it to the inner solar system about every 74 to 76 years. There's no way to tell yet how close it may be to the earth at that time. It was last visible in 1986.
How close it will be to Earth, and how visible, can't be determined until we get closer to that year, when we can measure how much its orbit has been modified by its pass through the outer planets.
Halley's Comet has an orbital period of 75.3 years. Look for the famous comet to pass Earth in the late summer of 2061.
Many comets are irregular - they may come back after millions of years, or not at all. So, it can't always be known in advance when there will be a comet.
2010 and then another on august 15 2011
Balls
Approximately every 76 years 1986 + 76 = 2062
Probably several times. It is assumed that a third of Earth water came from comets and it was a comet that hit the Earth 65 million years ago and caused the dinosaur extinction.
It takes roughly 75 years for Halley's comet to come by the earth. All comets orbit the sun, but they do not all originate from the same place, which accounts for their paths and how long their individual orbit takes.
HayleysComet will come about 2061!!!!!!!!!!!! It last came in 1986.
2061
Halleys comet comes back around every 76 years.
You will if you live to be 62 or 63 years old.
early 2062
That is Halley's comet, named after English astronomer Edmond Halley,
It takes 75 years
76 years
No, a comet will NOT hit earth in 2012.
Approximately every 76 years 1986 + 76 = 2062
Probably several times. It is assumed that a third of Earth water came from comets and it was a comet that hit the Earth 65 million years ago and caused the dinosaur extinction.
It takes roughly 75 years for Halley's comet to come by the earth. All comets orbit the sun, but they do not all originate from the same place, which accounts for their paths and how long their individual orbit takes.
Halley's Comet
Comet Lulin will not hit the Earth; it won't even come especially close.