Martian flashes

More observations of mysterious transient bright spots on Mars’s surface are needed

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MARS FLARE PREDICTIONS: OCTOBER TO NOVEMBER 2020

TITHONIUS LACUS (–11°, 85°)

NOVEMBER

NORTHERN SOLIS LACUS (–15°, 90°)

OCTOBER

Interesting observations have been made in the past of transient brightening events – flares on the Martian disc. The most plausible explanation for these is that they are caused by spectacular reflections from ice, possibly in fissures or craters on the surface or from hydrated mineral areas.

Observing these fascinating events requires a 150mm or larger scope, high magnification and preferably good seeing. It also helps to know the general period when they may occur. Two reported sites are at Tithonius Lacus and Edom Promontorium, a region between Sinus Sabaeus and Sinus Meridiani corresponding to Schiaparelli crater. Our analysis suggests Tithonius Lacus and a site north of Solis Lacus may produce glints this apparition.

There is no guarantee that these ‘ice glints’ will be observable using predictions and they have only been recorded on a few occasions. There are still many unknowns about them, including whether any reflecting material forms seasonally, and what the variance is in the angles of the reflective surfaces which cause the glints. Positive observations are very useful for making future predictions.

Four values are used to determine possible events: declination of Earth (De) and Sun (Ds) from Mars, central meridian (CM) and the Earth-Mars-Sun phase angle (i). Our table (left) shows some dates and times when it’s worth keeping an eye on the regions Tithonius Lacus and Northern Solis Lacus.

If a glint occurs it may present itself as a short-lived brightening in a region or a series of growing and dimming flashes. A flash may last for several seconds or even tens of seconds. Observing reports of these events may be done visually or using a camera. A photo sequence showing the flashes occurring at a high image scale would make a very valuable observation. Obviously, such a short-lived event means recording appearance times as accurately as possible, so it’s important to keep an accurate timepiece to hand and to set the imaging computer’s clock accurately.