At an equinox, the Sun is at one of two opposite points on the celestial sphere where the celestial equator ( i. e. declination 0 ) and ecliptic intersect.

At the magnetic dip equator, where the geomagnetic field is horizontal, this electric field results in an enhanced eastward current flow within ± 3 degrees of the magnetic equator, known as the equatorial electrojet.

At the onset of the Neoproterozoic the supercontinent Rodinia, which had assembled during the late Mesoproterozoic, straddled the equator.

At the high end of estimates for the rotation velocity for Vega is along the equator ( for a rotation period of about 12. 5 hours ), which is 87. 6 % of the speed that would cause the star to start breaking up from centrifugal effects.

At the poles, the troposphere is thinner and the temperature only decreases to-45 ° C, while at the equator the temperature at the top of the troposphere can reach-75 ° C.

At surface level, the sinking air diverges again with some moving back to the equator and completing the vertical cycle.

At their intersections with the celestial sphere, these form the celestial equator, the celestial poles and the ecliptic, respectively.

* At the equator objects on the celestial poles stay at fixed points on the horizon.

At the equator, under flat conditions ( no obstructions such as mountains ; or at a height above any such obstructions ), the terminator line moves at approximately 1600 kilometers per hour ( 1000 miles per hour ).

At almost 7, 000 feet above sea level and almost exactly halfway between the equator and north pole, West Yellowstone experiences a subarctic climate ( Köppen climate classification Dfc ) with cold, sometimes bitterly cold winters, and brief but generally warm summers.

At the equator this delay between fixes was several hours ; at mid-latitudes the delay decreased to an hour or two.

At the Earth's equator this circle vanishes to a single point – the celestial pole itself – which lies on the horizon, and there are therefore effectively no circumpolar stars at all.

At Oxford he extended the Cape observations of stars to the 7th magnitude from 25 ° S declination to the equator, and collected the results in the Radcliffe catalogue for 1890, which contains the places of 6, 424 stars.

At the equator, the effective gravitational acceleration is 9. 7805 m / s².

At geodetic latitude 48. 46791 … degrees ( e. g., Lèves, Alsace, France ), the radius R is 20000 / π ≈ 6, 366. 1977 …, namely the radius of a perfect sphere for which the meridian arc length from the equator to the North Pole is exactly 10000 km, the originally proposed definition of the meter.

At a declination of-29. 6 °, Fomalhaut is located south of the celestial equator, and hence is best viewed from the Southern Hemisphere.

( At the poles, though, the celestial equator would be parallel to the horizon.

) At all latitudes the celestial equator appears perfectly straight because the observer is only finitely far from the plane of the celestial equator but infinitely far from the celestial equator itself.

At the pole, the temperature may be above 20, 000 K, while the equator is at or below 10, 000 K. The average temperature of the star is about 15, 000 K. The high polar temperatures are generating a fast polar wind that is ejecting matter from the star, creating a polar envelope of hot gas and plasma.

At solar maximum, the Sun's magnetic field lines are the most distorted due to the magnetic field on the solar equator rotating at a slightly faster pace than at the solar poles.

At the equator, there is very little difference ( Pisces, Aries, Virgo and Libra take slightly less time than the other signs ) but as one moves from the equator, larger and larger differences emerge.

At her door, two or three hours later, Mary Jane whispered, `` Everyone is asleep ''.

At the end of this period two pious Christians in Rome receive the revelation which leads them to seek the next Pope on the rock.

At two thirty he sent Fujimoto to the top of the wall at the northeast corner of the mission to keep an eye on the ridge road and give a signal when he first glimpsed the approach of Kayabashi's party.

At 7:25 two hotel doormen came thumping down the steps, carrying a saw-horse to be set up as a barricade in front of the haberdashery store window next to the entranceway, and as I watched them in their gaudy red coats that nearly scraped the ground, their golden, fringed epaulets and spic, red-visored caps, I suddenly saw just over their shoulders Jessica gracefully making her way through the crowd.

At the age of 17 he became an apprentice machinist at the shop of Walcott & Harris in Valley Falls, Rhode Island, and following two or three other jobs in quick succession after graduation, he went into business for himself in 1831, making lathes and small tools.

At a very shallow place, two Mexicans rushed into the open for a shot.

At this moment, Loveless and Means arrived, crashing through the undergrowth with their horses, and distracted her, and she ran off a short distance and jumped into a crevice between two rocks.

At Jenks Street, Simms said, the car skidded completely around, just missed two parked cars, and sped east in Jenks.

At least two private colleges in the Atlanta area now or in the past have had integrated student bodies, but their tax-exempt status never has been challenged by the state.

At one extreme are the systems of upper New York State, where libraries in two or more counties combine to serve a large, sparsely populated area.

Those elegant `` At Home '' cards she sent out, now she could wear her pretty clothes again, and had the house all trimmed up, hadn't brought many callers in two whole months.

At two that morning, he was still walking -- up and down Peony, up and down the veranda, up and down the silent, moonlit beach.

At pH values between the two pKa values, the zwitterion predominates, but coexists in dynamic equilibrium with small amounts of net negative and net positive ions.

At the exact midpoint between the two pKa values, the trace amount of net negative and trace of net positive ions exactly balance, so that average net charge of all forms present is zero.

At one end of the shank there are two arms, carrying the flukes, while the stock is mounted to the other end, at ninety degrees to the arms.

At the time both South African and South American plants were placed in the same genus ; subsequently they were separated into two different genera.

At last, led to the Hippodrome of Constantinople, he was hung up by the feet between two pillars, and two Latin soldiers competed as to whose sword would penetrate his body more deeply, and finally his body, according to the representation of his death, was torn apart.

At no great distance east of this rift-valley is Mount Kilimanjaro-with its two peaks Kibo and Mawenzi, the latter being, and the culminating point of the whole continent — and Mount Kenya, which is.

At the end of day two, Apollo 16 was about away from Earth.

At that point, scientists began to reconsider their pre-mission hypothesis that Descartes had been the setting of ancient volcanic activity, as the two astronauts had yet to find any volcanic material.

At speaker meetings one or two members tell their stories, while discussion meetings allocate the most time for general discussion.

At some moment a price difference exists, and the problem is to execute two or three balancing transactions while the difference persists ( that is, before the other arbitrageurs act ).

At least two of the cellphone calls made by passengers indicate that all the hijackers they saw were wearing red bandanas, which some have questioned may have signified an allegiance to the Egyptian Islamic Jihad.

At least two of the cellphone calls made by passengers indicate that all the hijackers they saw were wearing red bandanas, which some believe may have signified an allegiance to the Egyptian Islamic Jihad.