The Global Citizen Plus

Physics lesson first: a gravity assist uses a planet’s pull to change a spacecraft’s path. NASA’s twin ESCAPADE spacecraft, whose full name is Escape and Plasma Acceleration and Dynamics Explorers, each flew past Earth this week and added a sustained engine burn of roughly nine minutes. That burn is the firing that commits each one to the road to Mars.

NASA says this is the first time it has used a powered Earth flyby to send a spacecraft toward Mars. The first spacecraft made its closest approach at about 5 a.m. EST on 7 November, roughly 1,000 miles above Earth’s surface. The second followed at about 6 a.m. EST on 9 November, roughly 650 miles above it.

The route is unusual. The pair launched on 13 November 2025 from Cape Canaveral Space Force Station in Florida, when Earth and Mars were on opposite sides of the Sun. Instead of flying straight to Mars, they entered a loiter orbit around Lagrange point 2, about a million miles from Earth, on a kidney-bean-shaped path.

Waiting there let the mission launch at nearly any time, rather than waiting for the roughly two-year window when Earth and Mars align for a direct launch. The cruise to Mars now takes about 10 months. Orbit insertion is planned for 7 and 9 September 2027, and each spacecraft will fire its engine for about 11 minutes to be captured by Mars’s gravity.

The science comes later. The two orbiters will fly in formation to study how the solar wind affects Mars’s environment and drives atmospheric loss. Science operations are expected to begin in June 2028.

Science lesson: the Air Quality Index (AQI) turns pollution measurements into one number. Higher is worse. On 6 November at 8 am, central monitors put Delhi’s overall AQI at 389, “very poor”, up from 369 the day before. Weekly averages rose from 324 on Monday to 350 on Tuesday and 377 on Wednesday.

Individual stations tell a sharper story. About 28 stations recorded “severe” air, above 400: IIT Delhi read 473, Jahangirpuri 460, RK Puram 446, Sirifort 431 and ITO 424. Others, like Anand Vihar at 359 and Badarpur at 352, were “very poor”.

Geography and weather explain why. Stubble burning was at its peak season. Firecracker emissions came with Diwali, along with vehicle pollution and weakening winds. Skymet’s Mahesh Palawat said moderate northwesterly winds would last until 7 November and light easterly winds from Diwali night might disperse pollutants on 8 November, but conditions could worsen from 9 November.

The Supreme Court allowed approved green firecrackers on 7 and 8 November only, from 6 am to 7 am and 8 pm to 10 pm, with enforcement and monitoring safeguards. CREA’s Manoj Kumar said some hotspots could exceed 450 and urged stricter GRAP measures, the city’s graded response plan.

Looking one day earlier shows how quickly things change. On 30 October air was “satisfactory”, with an AQI of 60, after rain linked to Cyclone Montha. Then it worsened fast: the 24-hour average rose to 350 on 3 November and 377 on 4 November, and on 4 November 22 of 59 stations recorded severe air.

The Decision Support System assigned 20.2% of Delhi’s pollution on 4 November to stubble burning and 15.5% to transport. Satellites detected 467 farm fires across six states that day, 151 of them in Punjab, and north-westerly winds carry that smoke toward Delhi. Between 15 September and 4 November, ICAR-IARI’s CREAMS Laboratory recorded 4,800 residue-burning events across seven states and UTs.

Health advice from the report: children, older adults and people with respiratory or heart conditions should limit outdoor exertion, use N95 masks outdoors where possible, and keep windows closed during peak smog hours.